Biodegradable lipids for delivery of nucleic acids

ABSTRACT

The present invention provides, in part, a biodegradable compound of formula I, and sub-formulas thereof: Formula (I) or a pharmaceutically acceptable salt thereof, where each X independently is O or S, each Y independently is O or S, and each R 1  independently is defined herein; and a liposome composition comprising the cationic lipid of formula I or a sub-formula thereof, and methods of delivering agents, such as nucleic acids including mRNA, in vivo, by administering to a subject the liposome comprising the cationic lipid of formula I or a sub-formula thereof, where the agent is encapsulated within the liposome.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/314,818, filed Nov. 29, 2016, which is the U.S. National Stage ofInternational Application No. PCT/US2015/033173, filed May 29, 2015,which claims priority under 35 U.S.C § 119(e) to U.S. ProvisionalApplication No. 62/005,266, filed on May 30, 2014, the disclosures ofwhich are incorporated herein by reference in their entirety.

BACKGROUND

The delivery of agents, such as nucleic acids, has been exploredextensively as a potential therapeutic option for certain diseasestates. In particular, RNA interference (RNAi) has been the subject ofsignificant research and clinical development. Lately, messenger RNA(mRNA) therapy has become an increasingly important option for treatmentof various diseases, in particular, for those associated with deficiencyof one or more proteins.

SUMMARY OF THE INVENTION

The present invention provides, among other things, a novel class oflipid compounds for improved in vivo delivery of therapeutic agents,such as nucleic acids. In particular, the compounds provided by thepresent invention are biodegradable in nature and are particularlyuseful for delivery of mRNA and other nucleic acids for therapeuticuses. It is contemplated that the compounds provided herein are capableof highly effective in vivo delivery while maintaining favorabletoxicity profile due to the biodegradable nature.

In one aspect, the present invention provides a compound (i.e., cationiclipid) of formula I:

or a pharmaceutically acceptable salt thereof,

wherein:

-   -   each X independently is O or S;    -   each Y independently is O or S; and    -   each R¹ independently is defined herein.

In some embodiments, the compound of formula I is of formula II:

or a pharmaceutically acceptable salt thereof,wherein:

-   -   each X independently is O or S;    -   each Y independently is O or S;    -   each m independently is 0 to 20;    -   each n independently is 1 to 6;    -   each R_(A) is independently hydrogen, optionally substituted        C1-50 alkyl, optionally substituted C2-50 alkenyl, optionally        substituted C2-50 alkynyl, optionally substituted C3-10        carbocyclyl, optionally substituted 3-14 membered heterocyclyl,        optionally substituted C6-14 aryl, optionally substituted 5-14        membered heteroaryl or halogen, and    -   each R_(B) is independently hydrogen, optionally substituted        C1-50 alkyl, optionally substituted C2-50 alkenyl, optionally        substituted C2-50 alkynyl, optionally substituted C3-10        carbocyclyl, optionally substituted 3-14 membered heterocyclyl,        optionally substituted C6-14 aryl, optionally substituted 5-14        membered heteroaryl or halogen.

In some embodiments, the compound has a structure of formula III (i.e.,Target 23 or T23):

or a pharmaceutically acceptable salt thereof.

In some embodiments, a compound of formula II is a compound of formulaIV (i.e., Target 24 or T24):

or a pharmaceutically acceptable salt thereof.

In some embodiments, a compound of formula II is a compound of formulaV:

or a pharmaceutically acceptable salt thereof.

In another aspect, the invention provides a composition, such as a lipidnanoparticle (e.g., liposome), comprising one or more of the compounds(i.e., cationic lipids) of formula I, formula II, formula III, formulaIV, formula V or a sub-formula thereof.

In some embodiments, a suitable composition of the present invention isa liposome. In some embodiments, a suitable liposome comprises one ormore cationic lipids of formula I, formula II, formula III, formula IV,formula V or a sub-formula thereof. In particular embodiments, asuitable liposome comprises a cationic lipid of formula III. Inparticular embodiments, a suitable liposome comprises a cationic lipidof formula IV. In particular embodiments, a suitable liposome comprisesa cationic lipid of formula V.

In some embodiments, a suitable liposome further comprises one or morenon-cationic lipids, one or more cholesterol-based lipids and/or one ormore PEG-modified lipids. In some embodiments, the one or morenon-cationic lipids are selected from distearoylphosphatidylcholine(DSPC), dioleoylphosphatidylcholine (DOPC),dipalmitoylphosphatidylcholine (DPPC), dioleoylphosphatidylglycerol(DOPG), dipalmitoylphosphatidyl-glycerol (DPPG),dioleoylphosphatidylethanolamine (DOPE),palmitoyloleoylphosphatidylcholine (POPC),palmitoyloleoyl-phosphatidylethanolamine (POPE),dioleoylphosphatidyl-ethanolamine4-(N-maleimidomethyl)-cyclohexane-1-carboxylate (DOPE-mal), dipalmitoylphosphatidyl ethanolamine (DPPE), dimyristoylphosphoethanolamine (DMPE),distearoyl-phosphatidylethanolamine (DSPE), 16-O-monomethyl PE,16-O-dimethyl PE, 18-1-trans PE,1-stearoyl-2-oleoyl-phosphatidyethanolamine (SOPE), or a mixturethereof.

In some embodiments, a suitable liposome further comprises one or morecholesterol-based lipids. In some embodiments, the one or morecholesterol-based lipids are selected from cholesterol, PEGylatedcholesterol and DC-Chol (N,N-dimethyl-N-ethylcarboxamidocholesterol),1,4-bis(3-N-oleylamino-propyl)piperazine.

In some embodiments, a suitable liposome further comprises one or morePEG-modified lipids. In some embodiments, the one or more PEG-modifiedlipids comprise a poly(ethylene) glycol chain of up to 5 kDa in lengthcovalently attached to a lipid with alkyl chain(s) of C₆-C₂₀ length. Insome embodiments, a PEG-modified lipid is a derivatized ceramide such asN-Octanoyl-Sphingosine-1-[Succinyl(Methoxy Polyethylene Glycol)-2000].In some embodiments, a PEG-modified or PEGylated lipid is PEGylatedcholesterol or Dimyristoylglycerol (DMG)-PEG-2K.

In some embodiments, a suitable liposome comprises the compound ofFormula III, DOPE, cholesterol and DMG-PEG2K.

In some embodiments, a suitable liposome has a size of or less thanabout 500 nm, 450 nm, 400 nm, 350 nm, 300 nm, 250 nm, 200 nm, 150 nm,125 nm, 110 nm, 100 nm, 95 nm, 90 nm, 85 nm, 80 nm, 75 nm, 70 nm, 65 nm,60 nm, 55 nm, or 50 nm.

In some embodiments, a liposome according to the present inventioncomprises an mRNA encoding a protein encapsulated therein.

In yet another aspect, the present invention provides methods ofdelivering a therapeutic agent, such as a nucleic acid (e.g., DNA,siRNA, mRNA, microRNA) using a composition (e.g., liposome) describedherein. In still another aspect, the present invention provides methodsof treating a disease or disorder including administering to subject inneed of treatment a composition (e.g., liposome) comprising atherapeutic agent, such as a nucleic acid (e.g., DNA, siRNA, mRNA,microRNA).

Other features, objects, and advantages of the present invention areapparent in the detailed description, drawings and claims that follow.It should be understood, however, that the detailed description, thedrawings, and the claims, while indicating embodiments of the presentinvention, are given by way of illustration only, not limitation.Various changes and modifications within the scope of the invention willbecome apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWING

Illustrated in FIG. 1 are human EPO levels in wild type mouse sera aftertreatment via hEPO mRNA loaded LNPs. Treatment after 6 hours is shown inthe bars at right. Treatment after 24 hours is shown in the bars atleft.

DEFINITIONS

In order for the present invention to be more readily understood,certain terms are first defined below. Additional definitions for thefollowing terms and other terms are set forth throughout thespecification. The publications and other reference materials referencedherein to describe the background of the invention and to provideadditional detail regarding its practice are hereby incorporated byreference.

Chemical Definitions

Definitions of specific functional groups and chemical terms aredescribed in more detail below. The chemical elements are identified inaccordance with the Periodic Table of the Elements, CAS version,Handbook of Chemistry and Physics, 75th Ed., inside cover, and specificfunctional groups are generally defined as described therein.Additionally, general principles of organic chemistry, as well asspecific functional moieties and reactivity, are described in OrganicChemistry, Thomas Sorrell, University Science Books, Sausalito, 1999;Smith and March March's Advanced Organic Chemistry, 5th Edition, JohnWiley & Sons, Inc., New York, 2001; Larock, Comprehensive OrganicTransformations, VCH Publishers, Inc., New York, 1989; and Carruthers,Some Modern Methods of Organic Synthesis, 3rd Edition, CambridgeUniversity Press, Cambridge, 1987.

Compounds described herein can comprise one or more asymmetric centers,and thus can exist in various isomeric forms, e.g., enantiomers and/ordiastereomers. For example, the compounds described herein can be in theform of an individual enantiomer, diastereomer or geometric isomer, orcan be in the form of a mixture of stereoisomers, including racemicmixtures and mixtures enriched in one or more stereoisomer. Isomers canbe isolated from mixtures by methods known to those skilled in the art,including chiral high performance liquid chromatography (HPLC) and theformation and crystallization of chiral salts; or preferred isomers canbe prepared by asymmetric syntheses. See, for example, Jacques et al.,Enantiomers, Racemates and Resolutions (Wiley Interscience, New York,1981); Wilen et al., Tetrahedron 33:2725 (1977); Eliel, E. L.Stereochemistry of Carbon Compounds (McGraw-Hill, N Y, 1962); and Wilen,S. H. Tables of Resolving Agents and Optical Resolutions p. 268 (E. L.Eliel, Ed., Univ. of Notre Dame Press, Notre Dame, Ind. 1972). Theinvention additionally contemplates compounds as individual isomerssubstantially free of other isomers, and alternatively, as mixtures ofvarious isomers.

When a range of values is listed, it is intended to encompass each valueand sub-range within the range. For example “C1-6 alkyl” is intended toencompass, C1, C2, C3, C4, C5, C6, C1-6, C1-5, C1-4, C1-3, C1-2, C2-6,C2-5, C2-4, C2-3, C3-6, C3-5, C3-4, C4-6, C4-5, and C5-6 alkyl.

As used herein, “alkyl” refers to a radical of a straight-chain orbranched saturated hydrocarbon group having from 1 to 50 carbon atoms(“C1-50 alkyl”). In some embodiments, an alkyl group has 1 to 40 carbonatoms (“C1-40 alkyl”). In some embodiments, an alkyl group has 1 to 30carbon atoms (“C1-30 alkyl”). In some embodiments, an alkyl group has 1to 20 carbon atoms (“C1-20 alkyl”). In some embodiments, an alkyl grouphas 1 to 10 carbon atoms (“C1-10 alkyl”). In some embodiments, an alkylgroup has 1 to 9 carbon atoms (“C1-9 alkyl”). In some embodiments, analkyl group has 1 to 8 carbon atoms (“C1-8 alkyl”). In some embodiments,an alkyl group has 1 to 7 carbon atoms (“C1-7 alkyl”). In someembodiments, an alkyl group has 1 to 6 carbon atoms (“C1-6 alkyl”). Insome embodiments, an alkyl group has 1 to 5 carbon atoms (“C1-5 alkyl”).In some embodiments, an alkyl group has 1 to 4 carbon atoms (“C1-4alkyl”). In some embodiments, an alkyl group has 1 to 3 carbon atoms(“C1-3 alkyl”). In some embodiments, an alkyl group has 1 to 2 carbonatoms (“C1-2 alkyl”). In some embodiments, an alkyl group has 1 carbonatom (“C1 alkyl”). In some embodiments, an alkyl group has 2 to 6 carbonatoms (“C2-6 alkyl”). Examples of C1-6 alkyl groups include, withoutlimitation, methyl (C1), ethyl (C2), n-propyl (C3), isopropyl (C3),n-butyl (C4), tert-butyl (C4), sec-butyl (C4), iso-butyl (C4), n-pentyl(C5), 3-pentanyl (C5), amyl (C5), neopentyl (C5), 3-methyl-2-butanyl(C5), tertiary amyl (C5), and n-hexyl (C6). Additional examples of alkylgroups include n-heptyl (C7), n-octyl (C8) and the like. Unlessotherwise specified, each instance of an alkyl group is independentlyunsubstituted (an “unsubstituted alkyl”) or substituted (a “substitutedalkyl”) with one or more substituents. In certain embodiments, the alkylgroup is an unsubstituted C1-50 alkyl. In certain embodiments, the alkylgroup is a substituted C1-50 alkyl.

As used herein, “heteroalkyl” refers to an alkyl group as defined hereinwhich further includes at least one heteroatom (e.g., 1 to 25, e.g., 1,2, 3, or 4 heteroatoms) selected from oxygen, sulfur, nitrogen, boron,silicon, and phosphorus within (i.e., inserted between adjacent carbonatoms of) and/or placed at one or more terminal position(s) of theparent chain. In certain embodiments, a heteroalkyl group refers to asaturated group having from 1 to 50 carbon atoms and 1 or moreheteroatoms within the parent chain (“heteroC1-50 alkyl”). In certainembodiments, a heteroalkyl group refers to a saturated group having from1 to 40 carbon atoms and 1 or more heteroatoms within the parent chain(“heteroC1-40 alkyl”). In certain embodiments, a heteroalkyl grouprefers to a saturated group having from 1 to 30 carbon atoms and 1 ormore heteroatoms within the parent chain (“heteroC1-30 alkyl”). Incertain embodiments, a heteroalkyl group refers to a saturated grouphaving from 1 to 20 carbon atoms and 1 or more heteroatoms within theparent chain (“heteroC1-20 alkyl”). In certain embodiments, aheteroalkyl group refers to a saturated group having from 1 to 10 carbonatoms and 1 or more heteroatoms within the parent chain (“heteroC1-10alkyl”). In some embodiments, a heteroalkyl group is a saturated grouphaving 1 to 9 carbon atoms and 1 or more heteroatoms within the parentchain (“heteroC1-9 alkyl”). In some embodiments, a heteroalkyl group isa saturated group having 1 to 8 carbon atoms and 1 or more heteroatomswithin the parent chain (“heteroC1-8 alkyl”). In some embodiments, aheteroalkyl group is a saturated group having 1 to 7 carbon atoms and 1or more heteroatoms within the parent chain (“heteroC1-7 alkyl”). Insome embodiments, a heteroalkyl group is a saturated group having 1 to 6carbon atoms and 1 or more heteroatoms within the parent chain(“heteroC1-6 alkyl”). In some embodiments, a heteroalkyl group is asaturated group having 1 to 5 carbon atoms and 1 or 2 heteroatoms withinthe parent chain (“heteroC1-5 alkyl”). In some embodiments, aheteroalkyl group is a saturated group having 1 to 4 carbon atoms and 1or 2 heteroatoms within the parent chain (“heteroC1-4 alkyl”). In someembodiments, a heteroalkyl group is a saturated group having 1 to 3carbon atoms and 1 heteroatom within the parent chain (“heteroC1-3alkyl”). In some embodiments, a heteroalkyl group is a saturated grouphaving 1 to 2 carbon atoms and 1 heteroatom within the parent chain(“heteroC1-2 alkyl”). In some embodiments, a heteroalkyl group is asaturated group having 1 carbon atom and 1 heteroatom (“heteroC1alkyl”). In some embodiments, a heteroalkyl group is a saturated grouphaving 2 to 6 carbon atoms and 1 or 2 heteroatoms within the parentchain (“heteroC2-6 alkyl”). Unless otherwise specified, each instance ofa heteroalkyl group is independently unsubstituted (an “unsubstitutedheteroalkyl”) or substituted (a “substituted heteroalkyl”) with one ormore substituents. In certain embodiments, the heteroalkyl group is anunsubstituted heteroC1-50 alkyl. In certain embodiments, the heteroalkylgroup is a substituted heteroC1-50 alkyl.

As used herein, “alkenyl” refers to a radical of a straight-chain orbranched hydrocarbon group having from 2 to 50 carbon atoms and one ormore carbon-carbon double bonds (e.g., 1, 2, 3, or 4 double bonds)(“C2-50 alkenyl”). In some embodiments, an alkenyl group has 2 to 40carbon atoms (“C2-40 alkenyl”). In some embodiments, an alkenyl grouphas 2 to 30 carbon atoms (“C2-30 alkenyl”). In some embodiments, analkenyl group has 2 to 20 carbon atoms (“C2-20 alkenyl”). In someembodiments, an alkenyl group has 2 to 10 carbon atoms (“C2-10alkenyl”). In some embodiments, an alkenyl group has 2 to 9 carbon atoms(“C2-9 alkenyl”). In some embodiments, an alkenyl group has 2 to 8carbon atoms (“C2-8 alkenyl”). In some embodiments, an alkenyl group has2 to 7 carbon atoms (“C2-7 alkenyl”). In some embodiments, an alkenylgroup has 2 to 6 carbon atoms (“C2-6 alkenyl”). In some embodiments, analkenyl group has 2 to 5 carbon atoms (“C2-5 alkenyl”). In someembodiments, an alkenyl group has 2 to 4 carbon atoms (“C2-4 alkenyl”).In some embodiments, an alkenyl group has 2 to 3 carbon atoms (“C2-3alkenyl”). In some embodiments, an alkenyl group has 2 carbon atoms (“C2alkenyl”). The one or more carbon-carbon double bonds can be internal(such as in 2-butenyl) or terminal (such as in 1-butenyl). Examples ofC2-4 alkenyl groups include, without limitation, ethenyl (C2),1-propenyl (C3), 2-propenyl (C3), 1-butenyl (C4), 2-butenyl (C4),butadienyl (C4), and the like. Examples of C2-6 alkenyl groups includethe aforementioned C2-4 alkenyl groups as well as pentenyl (C5),pentadienyl (C5), hexenyl (C6), and the like. Additional examples ofalkenyl include heptenyl (C7), octenyl (C8), octatrienyl (C8), and thelike. Unless otherwise specified, each instance of an alkenyl group isindependently unsubstituted (an “unsubstituted alkenyl”) or substituted(a “substituted alkenyl”) with one or more substituents. In certainembodiments, the alkenyl group is an unsubstituted C2-50 alkenyl. Incertain embodiments, the alkenyl group is a substituted C2-50 alkenyl.

As used herein, “heteroalkenyl” refers to an alkenyl group as definedherein which further includes at least one heteroatom (e.g., 1 to 25,e.g., 1, 2, 3, or 4 heteroatoms) selected from oxygen, sulfur, nitrogen,boron, silicon, and phosphorus within (i.e., inserted between adjacentcarbon atoms of) and/or placed at one or more terminal position(s) ofthe parent chain. In certain embodiments, a heteroalkenyl group refersto a group having from 2 to 50 carbon atoms, at least one double bond,and 1 or more heteroatoms within the parent chain (“heteroC2-50alkenyl”). In certain embodiments, a heteroalkenyl group refers to agroup having from 2 to 40 carbon atoms, at least one double bond, and 1or more heteroatoms within the parent chain (“heteroC2-40 alkenyl”). Incertain embodiments, a heteroalkenyl group refers to a group having from2 to 30 carbon atoms, at least one double bond, and 1 or moreheteroatoms within the parent chain (“heteroC2-30 alkenyl”). In certainembodiments, a heteroalkenyl group refers to a group having from 2 to 20carbon atoms, at least one double bond, and 1 or more heteroatoms withinthe parent chain (“heteroC2-20 alkenyl”). In certain embodiments, aheteroalkenyl group refers to a group having from 2 to 10 carbon atoms,at least one double bond, and 1 or more heteroatoms within the parentchain (“heteroC2-10 alkenyl”). In some embodiments, a heteroalkenylgroup has 2 to 9 carbon atoms at least one double bond, and 1 or moreheteroatoms within the parent chain (“heteroC2-9 alkenyl”). In someembodiments, a heteroalkenyl group has 2 to 8 carbon atoms, at least onedouble bond, and 1 or more heteroatoms within the parent chain(“heteroC2-8 alkenyl”). In some embodiments, a heteroalkenyl group has 2to 7 carbon atoms, at least one double bond, and 1 or more heteroatomswithin the parent chain (“heteroC2-7 alkenyl”). In some embodiments, aheteroalkenyl group has 2 to 6 carbon atoms, at least one double bond,and 1 or more heteroatoms within the parent chain (“heteroC2-6alkenyl”). In some embodiments, a heteroalkenyl group has 2 to 5 carbonatoms, at least one double bond, and 1 or 2 heteroatoms within theparent chain (“heteroC2-5 alkenyl”). In some embodiments, aheteroalkenyl group has 2 to 4 carbon atoms. at least one double bond,and for 2 heteroatoms within the parent chain (“heteroC2-4 alkenyl”). Insome embodiments, a heteroalkenyl group has 2 to 3 carbon atoms, atleast one double bond, and 1 heteroatom within the parent chain(“heteroC2-3 alkenyl”). In some embodiments, a heteroalkenyl group has 2to 6 carbon atoms, at least one double, bond, and 1 or 2 heteroatomswithin the parent chain (“heteroC2-6 alkenyl”). Unless otherwisespecified, each instance of a heteroalkenyl group is independentlyunsubstituted (an “unsubstituted heteroalkenyl”) or substituted (a“substituted heteroalkenyl”) with one or more substituents. In certainembodiments, the heteroalkenyl group is an unsubstituted heteroC2-50alkenyl. In certain embodiments, the heteroalkenyl group is asubstituted heteroC2-50 alkenyl.

As used herein, “alkynyl” refers to a radical of a straight-chain orbranched hydrocarbon group having from 2 to 50 carbon atoms and one ormore carbon-carbon triple bonds (e.g., 1, 2, 3, or 4 triple bonds) andoptionally one or more double bonds (e.g., 1, 2, 3, or 4 double bonds)(“C2-50 alkynyl”). An alkynyl group that has one or more triple bondsand one or more double bonds is also referred to as an “ene-yne”. Insome embodiments, an alkynyl group has 2 to 40 carbon atoms (“C2-40alkynyl”). In some embodiments, an alkynyl group has 2 to 30 carbonatoms (“C2-30 alkynyl”). In some embodiments, an alkynyl group has 2 to20 carbon atoms (“C2-20 alkynyl”). In some embodiments, an alkynyl grouphas 2 to 10 carbon atoms (“C2-10 alkynyl”). In some embodiments, analkynyl group has 2 to 9 carbon atoms (“C2-9 alkynyl”). In someembodiments, an alkynyl group has 2 to 8 carbon atoms (“C2-8 alkynyl”).In some embodiments, an alkynyl group has 2 to 7 carbon atoms (“C2-7alkynyl”). In some embodiments, an alkynyl group has 2 to 6 carbon atoms(“C2-6 alkynyl”). In some embodiments, an alkynyl group has 2 to 5carbon atoms (“C2-5 alkynyl”). In some embodiments, an alkynyl group has2 to 4 carbon atoms (“C2-4 alkynyl”). In some embodiments, an alkynylgroup has 2 to 3 carbon atoms (“C2-3 alkynyl”). In some embodiments, analkynyl group has 2 carbon atoms (“C2 alkynyl”). The one or morecarbon-carbon triple bonds can be internal (such as in 2-butynyl) orterminal (such as in 1-butynyl). Examples of C2-4 alkynyl groupsinclude, without limitation, ethynyl (C2), 1-propynyl (C3), 2-propynyl(C3), 1-butynyl (C4), 2-butynyl (C4), and the like. Examples of C2-6alkenyl groups include the aforementioned C2-4 alkynyl groups as well aspentynyl (C5), hexynyl (C6), and the like. Additional examples ofalkynyl include heptynyl (C7), octynyl (C8), and the like. Unlessotherwise specified, each instance of an alkynyl group is independentlyunsubstituted (an “unsubstituted alkynyl”) or substituted (a“substituted alkynyl”) with one or more substituents. In certainembodiments, the alkynyl group is an unsubstituted C2-50 alkynyl. Incertain embodiments, the alkynyl group is a substituted C2-50 alkynyl.

As used herein, “heteroalkynyl” refers to an alkynyl group as definedherein which further includes at least one heteroatom (e.g., 1 to 25,e.g., 1, 2, 3, or 4 heteroatoms) selected from oxygen, sulfur, nitrogen,boron, silicon, and phosphorus within (i.e., inserted between adjacentcarbon atoms of) and/or placed at one or more terminal position(s) ofthe parent chain. In certain embodiments, a heteroalkynyl group refersto a group having from 2 to 50 carbon atoms, at least one triple bond,and 1 or more heteroatoms within the parent chain (“heteroC2-50alkynyl”). In certain embodiments, a heteroalkynyl group refers to agroup having from 2 to 40 carbon atoms, at least one triple bond, and 1or more heteroatoms within the parent chain (“heteroC2-40 alkynyl”). Incertain embodiments, a heteroalkynyl group refers to a group having from2 to 30 carbon atoms, at least one triple bond, and 1 or moreheteroatoms within the parent chain (“heteroC2-30 alkynyl”). In certainembodiments, a heteroalkynyl group refers to a group having from 2 to 20carbon atoms, at least one triple bond, and 1 or more heteroatoms withinthe parent chain (“heteroC2-20 alkynyl”). In certain embodiments, aheteroalkynyl group refers to a group having from 2 to 10 carbon atoms,at least one triple bond, and 1 or more heteroatoms within the parentchain (“heteroC2-10 alkynyl”). In some embodiments, a heteroalkynylgroup has 2 to 9 carbon atoms, at least one triple bond, and 1 or moreheteroatoms within the parent chain (“heteroC2-9 alkynyl”). In someembodiments, a heteroalkynyl group has 2 to 8 carbon atoms, at least onetriple bond, and 1 or more heteroatoms within the parent chain(“heteroC2-8 alkynyl”). In some embodiments, a heteroalkynyl group has 2to 7 carbon atoms, at least one triple bond, and 1 or more heteroatomswithin the parent chain (“heteroC2-7 alkynyl”). In some embodiments, aheteroalkynyl group has 2 to 6 carbon atoms, at least one triple bond,and 1 or more heteroatoms within the parent chain (“heteroC2-6alkynyl”). In some embodiments, a heteroalkynyl group has 2 to 5 carbonatoms, at least one triple bond, and 1 or 2 heteroatoms within theparent chain (“heteroC2-5 alkynyl”). In some embodiments, aheteroalkynyl group has 2 to 4 carbon atoms, at least one triple bond,and for 2 heteroatoms within the parent chain (“heteroC2-4 alkynyl”). Insome embodiments, a heteroalkynyl group has 2 to 3 carbon atoms, atleast one triple bond, and 1 heteroatom within the parent chain(“heteroC2-3 alkynyl”). In some embodiments, a heteroalkynyl group has 2to 6 carbon atoms, at least one triple bond. and 1 or 2 heteroatomswithin the parent chain (“heteroC2-6 alkynyl”). Unless otherwisespecified, each instance of a heteroalkynyl group is independentlyunsubstituted (an “unsubstituted heteroalkynyl”) or substituted (a“substituted heteroalkynyl”) with one or more substituents. In certainembodiments, the heteroalkynyl group is an unsubstituted heteroC2-50alkynyl. In certain embodiments, the heteroalkynyl group is asubstituted heteroC2-50 alkynyl.

As used herein, “carbocyclyl” or “carbocyclic” refers to a radical of anon-aromatic cyclic hydrocarbon group having from 3 to 10 ring carbonatoms (“C3-10 carbocyclyl”) and zero heteroatoms in the non-aromaticring system. In some embodiments, a carbocyclyl group has 3 to 8 ringcarbon atoms (“C3-8 carbocyclyl”). In some embodiments, a carbocyclylgroup has 3 to 7 ring carbon atoms (“C3-7 carbocyclyl”). In someembodiments, a carbocyclyl group has 3 to 6 ring carbon atoms (“C3-6carbocyclyl”). In some embodiments, a carbocyclyl group has 4 to 6 ringcarbon atoms (“C4-6 carbocyclyl”). In some embodiments, a carbocyclylgroup has 5 to 6 ring carbon atoms (“C5-6 carbocyclyl”). In someembodiments, a carbocyclyl group has 5 to 10 ring carbon atoms (“C5-10carbocyclyl”). Exemplary C3-6 carbocyclyl groups include, withoutlimitation, cyclopropyl (C3), cyclopropenyl (C3), cyclobutyl (C4),cyclobutenyl (C4), cyclopentyl (C5), cyclopentenyl (C5), cyclohexyl(C6), cyclohexenyl (C6), cyclohexadienyl (C6), and the like. ExemplaryC3-8 carbocyclyl groups include, without limitation, the aforementionedC3-6 carbocyclyl groups as well as cycloheptyl (C7), cycloheptenyl (C7),cycloheptadienyl (C7), cycloheptatrienyl (C7), cyclooctyl (C8),cyclooctenyl (C8), bicyclo[2.2.1]heptanyl (C7), bicyclo[2.2.2]octanyl(C8), and the like. Exemplary C3-10 carbocyclyl groups include, withoutlimitation, the aforementioned C3-8 carbocyclyl groups as well ascyclononyl (C9), cyclononenyl (C9), cyclodecyl (C10), cyclodecenyl(C10), octahydro-1H-indenyl (C9), decahydronaphthalenyl (C10),spiro[4.5]decanyl (C10), and the like. As the foregoing examplesillustrate, in certain embodiments, the carbocyclyl group is eithermonocyclic (“monocyclic carbocyclyl”) or polycyclic (e.g., containing afused, bridged or spiro ring system such as a bicyclic system (“bicycliccarbocyclyl”) or tricyclic system (“tricyclic carbocyclyl”)) and can besaturated or can contain one or more carbon-carbon double or triplebonds. “Carbocyclyl” also includes ring systems wherein the carbocyclylring, as defined above, is fused with one or more aryl or heteroarylgroups wherein the point of attachment is on the carbocyclyl ring, andin such instances, the number of carbons continue to designate thenumber of carbons in the carbocyclic ring system. Unless otherwisespecified, each instance of a carbocyclyl group is independentlyunsubstituted (an “unsubstituted carbocyclyl”) or substituted (a“substituted carbocyclyl”) with one or more substituents. In certainembodiments, the carbocyclyl group is an unsubstituted C3-10carbocyclyl. In certain embodiments, the carbocyclyl group is asubstituted C3-10 carbocyclyl.

In some embodiments, “carbocyclyl” or “carbocyclic” is referred to as a“cycloalkyl”, i.e., a monocyclic, saturated carbocyclyl group havingfrom 3 to 10 ring carbon atoms (“C3-10 cycloalkyl”). In someembodiments, a cycloalkyl group has 3 to 8 ring carbon atoms (“C3-8cycloalkyl”). In some embodiments, a cycloalkyl group has 3 to 6 ringcarbon atoms (“C3-6, cycloalkyl”). In some embodiments, a cycloalkylgroup has 4 to 6 ring carbon atoms (“C4-6 cycloalkyl”). In someembodiments, a cycloalkyl group has 5 to 6 ring carbon atoms (“C5-6cycloalkyl”). In some embodiments, a cycloalkyl group has 5 to 10 ringcarbon atoms (“C5-10 cycloalkyl”). Examples of C5-6 cycloalkyl groupsinclude cyclopentyl (C5) and cyclohexyl (C5). Examples of C3-6cycloalkyl groups include the aforementioned C5-6 cycloalkyl groups aswell as cyclopropyl (C3) and cyclobutyl (C4). Examples of C3-8cycloalkyl groups include the aforementioned C3-6 cycloalkyl groups aswell as cycloheptyl (C7) and cyclooctyl (C8). Unless otherwisespecified, each instance of a cycloalkyl group is independentlyunsubstituted (an “unsubstituted cycloalkyl”) or substituted (a“substituted cycloalkyl”) with one or more substituents. In certainembodiments, the cycloalkyl group is an unsubstituted C3-10 cycloalkyl.In certain embodiments, the cycloalkyl group is a substituted C3-10cycloalkyl.

As used herein, “heterocyclyl” or “heterocyclic” refers to a radical ofa 3- to 14-membered non-aromatic ring system having ring carbon atomsand 1 or more (e.g., 1, 2, 3, or 4) ring heteroatoms, wherein eachheteroatom is independently selected from oxygen, sulfur, nitrogen,boron, silicon, and phosphorus (“3-14 membered heterocyclyl”). Inheterocyclyl groups that contain one or more nitrogen atoms, the pointof attachment can be a carbon or nitrogen atom, as valency permits. Aheterocyclyl group can either be monocyclic (“monocyclic heterocyclyl”)or polycyclic (e.g., a fused, bridged or spiro ring system such as abicyclic system (“bicyclic heterocyclyl”) or tricyclic system(“tricyclic heterocyclyl”)). and can be saturated or can contain one ormore carbon-carbon double or triple bonds. Heterocyclyl polycyclic ringsystems can include one or more heteroatoms in one or both rings.“Heterocyclyl” also includes ring systems wherein the heterocyclyl ring,as defined above, is fused with one or more carbocyclyl groups whereinthe point of attachment is either on the carbocyclyl or heterocyclylring, or ring systems wherein the heterocyclyl ring, as defined above,is fused with one or more aryl or heteroaryl groups, wherein the pointof attachment is on the heterocyclyl ring, and in such instances, thenumber of ring members continue to designate the number of ring membersin the heterocyclyl ring system. Unless otherwise specified, eachinstance of heterocyclyl is independently unsubstituted (an“unsubstituted heterocyclyl”) or substituted (a “substitutedheterocyclyl”) with one or more substituents. In certain embodiments,the heterocyclyl group is an unsubstituted 3-14 membered heterocyclyl.In certain embodiments, the heterocyclyl group is a substituted 3-14membered heterocyclyl.

In some embodiments, a heterocyclyl group is a 5-10 memberednon-aromatic ring system having ring carbon atoms and 1 or more (e.g.,1, 2, 3, or 4) ring heteroatoms, wherein each heteroatom isindependently selected from oxygen, sulfur, nitrogen, boron, silicon,and phosphorus (“5-10 membered heterocyclyl”). In some embodiments, aheterocyclyl group is a 5-8 membered non-aromatic ring system havingring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ring heteroatoms,wherein each heteroatom is independently selected from oxygen, sulfur,nitrogen, boron, silicon, and phosphorus (“5-8 membered heterocyclyl”).In some embodiments, a heterocyclyl group is a 5-6 membered non-aromaticring system having ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4)ring heteroatoms, wherein each heteroatom is independently selected fromoxygen, sulfur, nitrogen, boron, silicon, and phosphorus (“5-6 memberedheterocyclyl”). In some embodiments, the 5-6 membered heterocyclyl has 1or more (e.g., 1, 2, or 3) ring heteroatoms selected from oxygen,sulfur, nitrogen, boron, silicon, and phosphorus. In some embodiments,the 5-6 membered heterocyclyl has 1 or 2 ring heteroatoms selected fromoxygen, sulfur, nitrogen, boron, silicon, and phosphorus. In someembodiments, the 5-6 membered heterocyclyl has 1 ring heteroatomselected from oxygen, sulfur, nitrogen, boron, silicon, and phosphorus.

Exemplary 3-membered heterocyclyl groups containing 1 heteroatominclude, without limitation, azirdinyl, oxiranyl, thiorenyl. Exemplary4-membered heterocyclyl groups containing 1 heteroatom include, withoutlimitation, azetidinyl, oxetanyl and thietanyl. Exemplary 5-memberedheterocyclyl groups containing 1 heteroatom include, without limitation.tetrahydrofuranyl, dihydrofuranyl, tetrahydrothiophenyl,dihydrothiophenyl, pyrrolidinyl, dihydropyrrolyl and pyrrolyl-2,5-dione.Exemplary 5-membered heterocyclyl groups containing 2 heteroatomsinclude, without limitation, dioxolanyl, oxathiolanyl and dithiolanyl.Exemplary 5-membered heterocyclyl groups containing 3 heteroatomsinclude, without limitation, triazolinyl, oxadiazolinyl, andthiadiazolinyl. Exemplary 6-membered heterocyclyl groups containing 1heteroatom include, without limitation, piperidinyl, tetrahydropyranyl,dihydropyridinyl, and thianyl. Exemplary 6-membered heterocyclyl groupscontaining 2 heteroatoms include, without limitation, piperazinyl,morpholinyl, dithianyl, dioxanyl. Exemplary 6-membered heterocyclylgroups containing 2 heteroatoms include, without limitation,triazinanyl. Exemplary 7-membered heterocyclyl groups containing 1heteroatom include, without limitation, azepanyl, oxepanyl andthiepanyl. Exemplary 8-membered heterocyclyl groups containing 1heteroatom include, without limitation, azocanyl, oxecanyl andthiocanyl. Exemplary bicyclic heterocyclyl groups include, withoutlimitation, indolinyl, isoindolinyl, dihydrobenzofuranyl,dihydrobenzothienyl, tetrahydrobenzothienyl, tetrahydrobenzofuranyl,tetrahydroindolyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl,decahydroquinolinyl, decahydroisoquinolinyl, octahydrochromenyl,octahydroisochromenyl, decahydronaphthyridinyl,decahydro-1,8-naphthyridinyl, octahydropyrrolo[3,2-b]pyrrole, indolinyl,phthalimidyl, naphthalimidyl, chromanyl, chromenyl,1H-benzo[e][1,4]diazepinyl, 1,4,5,7-tetrahydropyrano[3,4-b] pyrrolyl,5,6-dihydro-4H-furo[3,2-b]pyrrolyl, 6,7-dihydro-5H-furo[3,2-b]pyranyl,5,7-dihydro-4H-thieno[2,3-c]pyranyl,2,3-dihydro-1H-pyrrolo[2,3-b]pyridinyl, 2,3-dihydrofuro[2,3-b]pyridinyl,4,5,6,7-tetrahydro-1H-pyrrolo-[2,3-b]pyridinyl,4,5,6,7-tetrahydrofuro[3,2-c]pyridinyl, 4,5,6,7-tetrahydrothieno[3,2-b]pyridinyl, 1,2,3,4-tetrahydro-1,6-naphthyridinyl, and the like.

As used herein, “aryl” refers to a radical of a monocyclic or polycyclic(e.g., bicyclic or tricyclic) 4n+2 aromatic ring system (e.g., having 6,10, or 14 π electrons shared in a cyclic array) having 6-14 ring carbonatoms and zero heteroatoms provided in the aromatic ring system (“C6-14aryl”). In some embodiments, an aryl group has 6 ring carbon atoms (“C6aryl”; e.g., phenyl). In some embodiments, an aryl group has 10 ringcarbon atoms (“C10 aryl”; e.g., naphthyl such as 1-naphthyl and2-naphthyl). In some embodiments, an aryl group has 14 ring carbon atoms(“C14 aryl”; e.g., anthracyl). “Aryl” also includes ring systems whereinthe aryl ring, as defined above, is fused with one or more carbocyclylor heterocyclyl groups wherein the radical or point of attachment is onthe aryl ring, and in such instances, the number of carbon atomscontinue to designate the number of carbon atoms in the aryl ringsystem. Unless otherwise specified, each instance of an aryl group isindependently unsubstituted (an “unsubstituted aryl”) or substituted (a“substituted aryl”) with one or more substituents. In certainembodiments, the aryl group is an unsubstituted C6-14 aryl. In certainembodiments, the aryl group is a substituted C6-14 aryl.

As used herein, “heteroaryl” refers to a radical of a 5-14 memberedmonocyclic or polycyclic (e.g., bicyclic or tricyclic) 4n+2 aromaticring system (e.g., having 6, 10, or 14 π electrons shared in a cyclicarray) having ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4 ringheteroatoms) ring heteroatoms provided in the aromatic ring system,wherein each heteroatom is independently selected from oxygen, sulfur,nitrogen, boron, silicon, and phosphorus (“5-14 membered heteroaryl”).In heteroaryl groups that contain one or more nitrogen atoms, the pointof attachment can be a carbon or nitrogen atom, as valency permits.Heteroaryl polycyclic ring systems can include one or more heteroatomsin one or both rings. “Heteroaryl” includes ring systems wherein theheteroaryl ring, as defined above, is fused with one or more carbocyclylor heterocyclyl groups wherein the point of attachment is on theheteroaryl ring, and in such instances, the number of ring memberscontinue to designate the number of ring members in the heteroaryl ringsystem. “Heteroaryl” also includes ring systems wherein the heteroarylring, as defined above, is fused with one or more aryl groups whereinthe point of attachment is either on the aryl or heteroaryl ring, and insuch instances, the number of ring members designates the number of ringmembers in the fused polycyclic (aryl/heteroaryl) ring system.Polycyclic heteroaryl groups wherein one ring does not contain aheteroatom (e.g., indolyl, quinolinyl, carbazolyl, and the like) thepoint of attachment can be on either ring, i.e., either the ring bearinga heteroatom (e.g., 2-indolyl) or the ring that does not contain aheteroatom (e.g., 5-indolyl).

In some embodiments, a heteroaryl group is a 5-10 membered aromatic ringsystem having ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ringheteroatoms provided in the aromatic ring system, wherein eachheteroatom is independently selected from oxygen, sulfur, nitrogen,boron, silicon, and phosphorus (“5-10 membered heteroaryl”). In someembodiments, a heteroaryl group is a 5-8 membered aromatic ring systemhaving ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ringheteroatoms provided in the aromatic ring system, wherein eachheteroatom is independently selected from oxygen, sulfur, nitrogen,boron, silicon, and phosphorus (“5-8 membered heteroaryl”). In someembodiments, a heteroaryl group is a 5-6 membered aromatic ring systemhaving ring carbon atoms and 1 or more (e.g., 1, 2, 3, or 4) ringheteroatoms provided in the aromatic ring system, wherein eachheteroatom is independently selected from oxygen, sulfur, nitrogen,boron, silicon, and phosphorus (“5-6 membered heteroaryl”). In someembodiments, the 5-6 membered heteroaryl has 1 or more (e.g., 1, 2, or3) ring heteroatoms selected from oxygen, sulfur, nitrogen, boron,silicon, and phosphorus. In some embodiments, the 5-6 memberedheteroaryl has 1 or 2 ring heteroatoms selected from oxygen, sulfur,nitrogen, boron, silicon, and phosphorus. In some embodiments, the 5-6membered heteroaryl has 1 ring heteroatom selected from oxygen, sulfur,nitrogen, boron, silicon, and phosphorus. Unless otherwise specified,each instance of a heteroaryl group is independently unsubstituted (an“unsubstituted heteroaryl”) or substituted (a “substituted heteroaryl”)with one or more substituents. In certain embodiments, the heteroarylgroup is an unsubstituted 5-14 membered heteroaryl. In certainembodiments, the heteroaryl group is a substituted 5-14 memberedheteroaryl.

Exemplary 5-membered heteroaryl groups containing 1 heteroatom include,without limitation, pyrrolyl, furanyl and thiophenyl. Exemplary5-membered heteroaryl groups containing 2 heteroatoms include, withoutlimitation, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, andisothiazolyl. Exemplary 5-membered heteroaryl groups containing 3heteroatoms include, without limitation, triazolyl, oxadiazolyl, andthiadiazolyl. Exemplary 5-membered heteroaryl groups containing 4heteroatoms include, without limitation, tetrazolyl. Exemplary6-membered heteroaryl groups containing 1 heteroatom include, withoutlimitation. pyridinyl. Exemplary 6-membered heteroaryl groups containing2 heteroatoms include, without limitation, pyridazinyl, pyrimidinyl, andpyrazinyl. Exemplary 6-membered heteroaryl groups containing 3 or 4heteroatoms include, without limitation, triazinyl and tetrazinyl,respectively. Exemplary 7-membered heteroaryl groups containing 1heteroatom include, without limitation, azepinyl, oxepinyl, andthiepinyl. Exemplary 5,6-bicyclic heteroaryl groups include, withoutlimitation, indolyl, isoindolyl, indazolyl, benzotriazolyl,benzothiophenyl, isobenzothiophenyl, benzofuranyl, benzoisofuranyl,benzimidazolyl, benzoxazolyl, benzisoxazolyl, benzoxadiazolyl,benzthiazolyl, benzisothiazolyl, benzthiadiazolyl, indolizinyl, andpurinyl. Exemplary 6,6-bicyclic heteroaryl groups include, withoutlimitation, naphthyridinyl, pteridinyl, quinolinyl, isoquinolinyl,cinnolinyl, quinoxalinyl, phthalazinyl, and quinazolinyl. Exemplarytricyclic heteroaryl groups include, without limitation,phenanthridinyl, dibenzofuranyl, carbazolyl, acridinyl, phenothiazinyl,phenoxazinyl and phenazinyl.

As used herein, the term “partially unsaturated” refers to a ring moietythat includes at least one double or triple bond. The term “partiallyunsaturated” is intended to encompass rings having multiple sites ofunsaturation, but is not intended to include aromatic groups (e.g., arylor heteroaryl moieties) as herein defined.

As used herein, the term “saturated” refers to a ring moiety that doesnot contain a double or triple bond, i.e., the ring contains all singlebonds.

Affixing the suffix “-ene” to a group indicates the group is a divalentmoiety, e.g., alkylene is the divalent moiety of alkyl, alkenylene isthe divalent moiety of alkenyl,

alkynylene is the divalent moiety of alkynyl, heteroalkylene is thedivalent moiety of heteroalkyl, heteroalkenylene is the divalent moietyof heteroalkenyl, heteroalkynylene is the divalent moiety ofheteroalkynyl, carbocyclylene is the divalent moiety of carbocyclyl,heterocyclylene is the divalent moiety of heterocyclyl, arylene is thedivalent moiety of aryl, and heteroarylene is the divalent moiety ofheteroaryl.

As understood from the above, alkyl, alkenyl, alkynyl, heteroalkyl,heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, andheteroaryl groups, as defined herein, are, in certain embodiments,optionally substituted. Optionally substituted refers to a group whichmay be substituted or unsubstituted (e.g., “substituted” or“unsubstituted” alkyl, “substituted” or “unsubstituted” alkenyl,“substituted” or “unsubstituted” alkynyl, “substituted” or“unsubstituted” heteroalkyl, “substituted” or “unsubstituted”heteroalkenyl, “substituted” or “unsubstituted” heteroalkynyl.“substituted” or “unsubstituted” carbocyclyl. “substituted” or“unsubstituted” heterocyclyl, “substituted” or “unsubstituted” aryl or“substituted” or “unsubstituted” heteroaryl group). In general, the term“substituted” means that at least one hydrogen present on a group isreplaced with a permissible substituent, e.g., a substituent which uponsubstitution results in a stable compound, e.g., a compound which doesnot spontaneously undergo transformation such as by rearrangement,cyclization, elimination, or other reaction. Unless otherwise indicated,a “substituted” group has a substituent at one or more substitutablepositions of the group, and when more than one position in any givenstructure is substituted, the substituent is either the same ordifferent at each position. The term “substituted” is contemplated toinclude substitution with all permissible substituents of organiccompounds, any of the substituents described herein that results in theformation of a stable compound. The present invention contemplates anyand all such combinations in order to arrive at a stable compound. Forpurposes of this invention, heteroatoms such as nitrogen may havehydrogen substituents and/or any suitable substituent as describedherein which satisfy the valencies of the heteroatoms and results in theformation of a stable moiety.

Exemplary carbon atom substituents include, but are not limited to,halogen, —CN, —NO2, —N3, —SO2H, —SO3H, —OH, —ORaa, —ON(Rbb)2, —N(Rbb)2,—N(Rbb)3+X—, —N(ORcc)Rbb, —SeH, —SeRaa, —SH, —SRaa, —SSRcc, —C(═O)Raa,—CO2H, —CHO, —C(ORcc)2, —CO2Raa, —OC(═O)Raa, —OCO2Raa, —C(═O)N(Rbb)2,—OC(═O)N(Rbb)2, —NRbbC(═O)Raa, —NRbbCO2Raa, —NRbbC(═O)N(Rbb)2,—C(═NRbb)Raa, —C(═NRbb)ORaa, —OC(═NRbb)Raa, —OC(═NRbb)ORaa,—C(═NRbb)N(Rbb)2, —OC(═NRbb)N(Rbb)2, —NRbbC(═NRbb)N(Rbb)2,—C(═O)NRbbSO2Raa, —NRbbSO2Raa, —SO2N(Rbb)2, —SO2Raa, —SO2ORaa, —OSO2Raa,—S(═O)Raa, —OS(═O)Raa, —Si(Raa)3-OSi(Raa)3-C(═S)N(Rbb)2, —C(═O)SRaa,—C(═S)SRaa, —SC(═S)SRaa, —SC(═O)SRaa, —OC(═O)SRaa, —SC(═O)ORaa,—SC(═O)Raa, —P(═O)2Raa, —OP(═O)2Raa, —P(═O)(Raa)2, —OP(═O)(Raa)2,—OP(═O)(ORcc)2, —P(═O)2N(Rbb)2, —OP(═O)2N(Rbb)2, —P(═O)(NRbb)2,—OP(═O)(NRbb)2, —NRbbP(═O)(ORcc)2, —NRbbP(═O)(NRbb)2, —P(Rcc)2,—P(Rcc)3, —OP(Rcc)2, —OP(Rcc)3, —B(Raa)2, —B(ORcc)2, —BRaa(ORcc), C1-50alkyl, C2-50 alkenyl, C2-50 alkynyl, C3-14 carbocyclyl, 3-14 memberedheterocyclyl, C6-14 aryl, and 5-14 membered heteroaryl, wherein eachalkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroarylis independently substituted with 0, 1, 2, 3, 4, or 5 Rdd groups;

or two geminal hydrogens on a carbon atom are replaced with the group═O, ═S, ═NN(Rbb)2, ═NNRbbC(═O)Raa, ═NNRbbC(═O)ORaa, ═NNRbbS(═O)2Raa,═NRbb, or ═NORcc;

each instance of Raa is, independently, selected from C1-50 alkyl, C2-50alkenyl, C2-50 alkynyl, C3-10 carbocyclyl, 3-14 membered heterocyclyl,C6-14 aryl, and 5-14 membered heteroaryl, or two Raa groups are joinedto form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring,wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl,and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups;

each instance of Rbb is, independently, selected from hydrogen, —OH,—ORaa, —N(Rcc)2, —CN, —C(═O)Raa, —C(═O)N(Rcc)2, —CO2Raa, —SO2Raa,—C(═NRcc)ORaa, —C(═NRcc)N(Rcc)2, —SO2N(Rcc)2, —SO2Rcc, —SO20Rcc, —SORaa,—C(═S)N(Rcc)2, —C(═O)SRcc, —C(═S)SRcc, —P(═O)2Raa, —P(═O)(Raa)2,—P(═O)2N(Rcc)2, —P(═O)(NRcc)2, C1-50 alkyl, C2-50 alkenyl, C2-50alkynyl, C3-10 carbocyclyl, 3-14 membered heterocyclyl, C6-14 aryl, and5-14 membered heteroaryl, or two Rbb groups, together with theheteroatom to which they are attached, form a 3-14 membered heterocyclylor 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl,carbocyclyl, heterocyclyl, aryl, and heteroaryl is independentlysubstituted with 0, 1, 2, 3, 4, or 5 Rdd groups;

each instance of Rcc is, independently, selected from hydrogen, C1-50alkyl, C2-50 alkenyl, C2-50 alkynyl, C3-10 carbocyclyl, 3-14 memberedheterocyclyl, C6-14 aryl, and 5-14 membered heteroaryl, or two Rccgroups, together with the heteroatom to which they are attached, form a3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, whereineach alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, andheteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups;

each instance of Rdd is, independently, selected from halogen, —CN,—NO2, —N3, —SO2H, —SO3H, —OH, —ORee, —ON(Rff)2, —N(Rff)2, —N(Rff)3+X—,—N(ORee)Rff, —SH, —SRee, —SSRee, —C(═O)Ree, —CO2H, —CO2Ree, —OC(═O)Ree,—OCO2Ree, —C(═O)N(Rff)2, —OC(═O)N(Rff)2, —NRffC(═O)Ree, —NRffCO2Ree,—NRffC(═O)N(Rff)2, —C(═NRff)ORee, —OC(═NRff)Ree, —OC(═NRff)ORee,—C(═NRff)N(Rff)2, —OC(═NRff)N(Rff)2, —NRffC(═NRff)N(Rff)2, —NRffSO2Ree,—SO2N(Rff)2, —SO2Ree, —SO2ORee, —OSO2Ree, —S(═O)Ree, —Si(Ree)3,—OSi(Ree)3, —C(═S)N(Rff)2, —C(═O)SRee, —C(═S)SRee, —SC(═S)SRee,—P(═O)2Ree, —P(═O)(Ree)2, —OP(═O)(Ree)2, —OP(═O)(ORee)2, C1-50 alkyl,C2-50 alkenyl, C2-50 alkynyl, C3-10 carbocyclyl, 3-10 memberedheterocyclyl, C6-10 aryl, 5-10 membered heteroaryl, wherein each alkyl,alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl isindependently substituted with 0, 1, 2, 3, 4, or 5 Rgg groups, or twogeminal Rdd substituents can be joined to form ═O or ═S;

each instance of Ree is, independently, selected from C1-50 alkyl, C2-50alkenyl, C2-50 alkynyl, C3-10 carbocyclyl, C6-10 aryl, 3-10 memberedheterocyclyl, and 3-10 membered heteroaryl, wherein each alkyl, alkenyl,alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl isindependently substituted with 0, 1, 2, 3, 4, or 5 Rgg groups;

each instance of Rff is, independently, selected from hydrogen, C1-50alkyl, C2-50 alkenyl, C2-50 alkynyl, C3-10 carbocyclyl, 3-10 memberedheterocyclyl, C6-10 aryl and 5-10 membered heteroaryl, or two Rffgroups, together with the heteroatom to which they are attached, form a3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, whereineach alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, andheteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rgggroups; and

each instance of Rgg is, independently, halogen, —CN, —NO2, —N3, —SO2H,—SO3H, —OH, —OC1-50 alkyl, —ON(C1-50 alkyl)2, —N(C1-50 alkyl)2, —N(C1-50alkyl)3+X—, —NH(C1-50 alkyl)2+X—, —NH2(C1-50 alkyl)+X—, —NH3+X—,—N(OC1-50 alkyl)(C1-50 alkyl), —N(OH)(C1-50 alkyl), —NH(OH), —SH,—SC1-50 alkyl, —SS(C1-50 alkyl), —C(═O)(C1-50 alkyl), —CO2H, —CO2(C1-50alkyl), —OC(═O)(C1-50 alkyl), —OCO2(C1-50 alkyl), —C(═O)NH2,—C(═O)N(C1-50 alkyl)2, —OC(═O)NH(C1-50 alkyl), —NHC(═O)(C1-50 alkyl),—N(C1-50 alkyl)C(═O)(C1-50 alkyl), —NHCO2(C1-50 alkyl), —NHC(═O)N(C1-50alkyl)2, —NHC(═O)NH(C1-50 alkyl), —NHC(═O)NH2, —C(═NH)O(C1-50 alkyl),—OC(═NH)(C1-50 alkyl), —OC(═NH)OC1-50 alkyl, —C(═NH)N(C1-50 alkyl)2,—C(═NH)NH(C1-50 alkyl), —C(═NH)NH2, —OC(═NH)N(C1-50alkyl)2,—OC(NH)NH(C1-50 alkyl), —OC(NH)NH2, —NHC(NH)N(C1-50 alkyl)2,—NHC(═NH)NH2, —NHSO2 (C1-50 alkyl), —SO2N(C1-50 alkyl)2, —SO2NH(C1-50alkyl), —SO2NH2, —SO2C1-50 alkyl, —SO2OC1-50 alkyl, —OSO2C1-6 alkyl,—SOC1-6 alkyl, —Si(C1-50 alkyl)3, —OSi(C1-6 alkyl)3-C(═S)N(C1-50alkyl)2, C(═S)NH(C1-50 alkyl), C(═S)NH2, —C(═O)S(C1-6 alkyl),—C(═S)SC1-6 alkyl, —SC(═S)SC1-6 alkyl, —P(═O)2(C1-50 alkyl),—P(═O)(C1-50 alkyl)2, —OP(═O)(C1-50 alkyl)2, —OP(═O)(OC1-50 alkyl)2,C1-50 alkyl, C2-50 alkenyl, C2-50 alkynyl, C3-10 carbocyclyl, C6-10aryl, 3-10 membered heterocyclyl, 5-10 membered heteroaryl; or twogeminal Rgg substituents can be joined to form ═O or ═S; wherein X— is acounterion.

As used herein, the term “halo” or “halogen” refers to fluorine (fluoro,—F), chlorine (chloro, —Cl), bromine (bromo, —Br), or iodine (iodo, —I).

As used herein, a “counterion” is a negatively charged group associatedwith a positively charged quarternary amine in order to maintainelectronic neutrality. Exemplary counterions include halide ions (e.g.,F—, Cl—, Br—, I—), NO3-, ClO4-, OH—, H2PO4-, HSO4-, sulfonate ions(e.g., methansulfonate, trifluoromethanesulfonate, p-toluenesulfonate,benzenesulfonate, 10-camphor sulfonate, naphthalene-2-sulfonate,naphthalene-1-sulfonic acid-5-sulfonate, ethan-1-sulfonicacid-2-sulfonate, and the like), and carboxylate ions (e.g., acetate,ethanoate, propanoate, benzoate, glycerate, lactate, tartrate,glycolate, and the like).

Nitrogen atoms can be substituted or unsubstituted as valency permits,and include primary, secondary, tertiary, and quarternary nitrogenatoms. Exemplary nitrogen atom substitutents include, but are notlimited to, hydrogen, —OH, —ORaa, —N(Rcc)2, —CN, —C(═O)Raa,—C(═O)N(Rcc)2, —CO2Raa, —SO2Raa, —C(═NRbb)Raa, —C(═NRcc)ORaa,—C(═NRcc)N(Rcc)2, —SO2N(Rcc)2, —SO2Rcc, —SO2ORcc, —SORaa, —C(═S)N(Rcc)2,—C(═O)SRcc, —C(═S)SRcc, —P(═O)2Raa, —P(═O)(Raa)2, —P(═O)2N(Rcc)2,—P(═O)(NRcc)2, C1-50 alkyl, C2-50 alkenyl, C2-50 alkynyl, C3-10carbocyclyl, 3-14 membered heterocyclyl, C6-14 aryl, and 5-14 memberedheteroaryl, or two Rcc groups, together with the N atom to which theyare attached, form a 3-14 membered heterocyclyl or 5-14 memberedheteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl,heterocyclyl, aryl, and heteroaryl is independently substituted with 0,1, 2, 3, 4, or 5 Rdd groups, and wherein Raa, Rbb, Rcc and Rdd are asdefined above.

Nitrogen atoms can be substituted or unsubstituted as valency permits,and include primary, secondary, tertiary, and quarternary nitrogenatoms. Exemplary nitrogen atom substitutents include, but are notlimited to, hydrogen, —OH, —ORaa, —N(Rcc)2, —CN, —C(═O)Raa,—C(═O)N(Rcc)2, —CO2Raa, —SO2Raa, —C(═NRbb)Raa, —C(═NRcc)ORaa,—C(═NRcc)N(Rcc)2, —SO2N(Rcc)2, —SO2Rcc, —SO2ORcc, —SORaa, —C(═S)N(Rcc)2,—C(═O)SRcc, —C(═S)SRcc, —P(═O)2Raa, —P(═O)(Raa)2, —P(═O)2N(Rcc)2,—P(═O)(NRcc)2, C1-10 alkyl, C1-10 perhaloalkyl, C2-10 alkenyl, C2-10alkynyl, C3-10 carbocyclyl, 3-14 membered heterocyclyl, C6-14 aryl, and5-14 membered heteroaryl, or two Rcc groups, together with the nitrogenatom to which they are attached, form a 3-14 membered heterocyclyl or5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl,carbocyclyl, heterocyclyl, aryl, and heteroaryl is independentlysubstituted with 0, 1, 2, 3, 4, or 5 Rdd groups, and wherein Raa, Rbb,Rcc and Rdd are as defined above.

In certain embodiments, the substituent present on a nitrogen atom is anitrogen protecting group (also referred to as an amino protectinggroup). Nitrogen protecting groups include, but are not limited to, —OH,—ORaa, —N(Rcc)2, —C(═O)Raa, —C(═O)N(Rcc)2, —CO2Raa, —SO2Raa,—C(═NRcc)Raa, —C(═NRcc)ORaa, —C(═NRcc)N(Rcc)2, —SO2N(Rcc)2, —SO2Rcc,—SO2ORcc, —SORaa, —C(═S)N(Rcc)2, —C(═O)SRcc, —C(═S)SRcc, C1-10 alkyl(e.g., aralkyl, heteroaralkyl), C2-10 alkenyl, C2-10 alkynyl, C3-10carbocyclyl, 3-14 membered heterocyclyl, C6-14 aryl, and 5-14 memberedheteroaryl groups, wherein each alkyl, alkenyl, alkynyl, carbocyclyl,heterocyclyl, aralkyl, aryl, and heteroaryl is independently substitutedwith 0, 1, 2, 3, 4 or 5 Rdd groups, and wherein Raa, Rbb, Rcc and Rddare as defined herein. Nitrogen protecting groups are well known in theart and include those described in detail in Protecting Groups inOrganic Synthesis, T. W. Greene and P. G. M. Wuts, 3rd edition, JohnWiley & Sons, 1999, incorporated herein by reference.

For example, nitrogen protecting groups such as amide groups (e.g.,—C(═O)Raa) include, but are not limited to, formamide, acetamide,chloroacetamide, trichloroacetamide, trifluoroacetamide,phenylacetamide, 3-phenylpropanamide, picolinamide,3-pyridylcarboxamide, N-benzoylphenylalanyl derivative, benzamide,p-phenylbenzamide, o-nitophenylacetamide, o-nitrophenoxyacetamide,acetoacetamide, (N′-dithiobenzyloxyacylamino)acetamide,3-(p-hydroxyphenyl)propanamide, 3-(o-nitrophenyl)propanamide,2-methyl-2-(o-nitrophenoxy)propanamide,2-methyl-2-(o-phenylazophenoxy)propanamide, 4-chlorobutanamide,3-methyl-3-nitrobutanamide, o-nitrocinnamide, N-acetylmethioninederivative, o-nitrobenzamide and o-(benzoyloxymethyl)benzamide.

Nitrogen protecting groups such as carbamate groups (e.g., —C(═O)ORaa)include, but are not limited to, methyl carbamate, ethyl carbamante,9-fluorenylmethyl carbamate (Fmoc), 9-(2-sulfo)fluorenylmethylcarbamate, 9-(2,7-dibromo)fluoroenylmethyl carbamate,2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothioxanthyl)]methylcarbamate (DBD-Tmoc), 4-methoxyphenacyl carbamate (Phenoc),2,2,2-trichloroethyl carbamate (Troc), 2-trimethylsilylethyl carbamate(Teoc), 2-phenylethyl carbamate (hZ), 1-(1-adamantyl)-1-methylethylcarbamate (Adpoc), 1,1-dimethyl-2-haloethyl carbamate,1,1-dimethyl-2,2-dibromoethyl carbamate (DB-t-BOC),1,1-dimethyl-2,2,2-trichloroethyl carbamate (TCBOC),1-methyl-1-(4-biphenylyl)ethyl carbamate (Bpoc),1-(3,5-di-t-butylphenyl)-1-methylethyl carbamate (t-Bumeoc), 2-(2′- and4′-pyridyl)ethyl carbamate (Pyoc), 2-(N,N-dicyclohexylcarboxamido)ethylcarbamate, t-butyl carbamate (BOC), 1-adamantyl carbamate (Adoc), vinylcarbamate (Voc), allyl carbamate (Alloc), 1-isopropylallyl carbamate(Ipaoc), cinnamyl carbamate (Coc), 4-nitrocinnamyl carbamate (Noc),8-quinolyl carbamate, N-hydroxypiperidinyl carbamate, alkyldithiocarbamate, benzyl carbamate (Cbz), p-methoxybenzyl carbamate (Moz),p-nitobenzyl carbamate, p-bromobenzyl carbamate, p-chlorobenzylcarbamate, 2,4-dichlorobenzyl carbamate, 4-methylsulfinylbenzylcarbamate (Msz), 9-anthrylmethyl carbamate, diphenylmethyl carbamate,2-methylthioethyl carbamate, 2-methylsulfonylethyl carbamate,2-(p-toluenesulfonyl)ethyl carbamate, [2-(1,3-dithianyl)]methylcarbamate (Dmoc), 4-methylthiophenyl carbamate (Mtpc),2,4-dimethylthiophenyl carbamate (Bmpc), 2-phosphonioethyl carbamate(Peoc), 2-triphenylphosphonioisopropyl carbamate (Ppoc),1,1-dimethyl-2-cyanoethyl carbamate, m-chloro-p-acyloxybenzyl carbamate,p-(dihydroxyboryl)benzyl carbamate, 5-benzisoxazolylmethyl carbamate,2-(trifluoromethyl)-6-chromonylmethyl carbamate (Tcroc), m-nitrophenylcarbamate, 3,5-dimethoxybenzyl carbamate, o-nitrobenzyl carbamate,3,4-dimethoxy-6-nitrobenzyl carbamate, phenyl(o-nitrophenyl)methylcarbamate, t-amyl carbamate, S-benzyl thiocarbamate, p-cyanobenzylcarbamate, cyclobutyl carbamate, cyclohexyl carbamate, cyclopentylcarbamate, cyclopropylmethyl carbamate, p-decyloxybenzyl carbamate,2,2-dimethoxyacylvinyl carbamate, o-(N,N-dimethylcarboxamido)benzylcarbamate, 1,1-dimethyl-3-(N,N-dimethylcarboxamido)propyl carbamate,1,1-dimethylpropynyl carbamate, di(2-pyridyl)methyl carbamate,2-furanylmethyl carbamate, 2-iodoethyl carbamate, isobornyl carbamate,isobutyl carbamate, isonicotinyl carbamate,p-(p′-methoxyphenylazo)benzyl carbamate, 1-methylcyclobutyl carbamate,1-methylcyclohexyl carbamate, 1-methyl-1-cyclopropylmethyl carbamate,1-methyl-1(3,5-dimethoxyphenyl)ethyl carbamate,1-methyl-1-(p-phenylazophenyl)ethyl carbamate, 1-methyl-1-phenylethylcarbamate, 1-methyl-1-(4-pyridyl)ethyl carbamate, phenyl carbamate,p-(phenylazo)benzyl carbamate, 2,4,6-tri-t-butylphenyl carbamate,4-(trimethylammonium)benzyl carbamate, and 2,4,6-trimethylbenzylcarbamate.

Nitrogen protecting groups such as sulfonamide groups (e.g., —S(═O)2Raa)include, but are not limited to, p-toluenesulfonamide (Ts),benzenesulfonamide, 2,3,6,-trimethyl-4-methoxybenzenesulfonamide (Mtr),2,4,6-trimethoxybenzenesulfonamide (Mtb),2,6-dimethyl-4-methoxybenzenesulfonamide (Pme),2,3,5,6-tetramethyl-4-methoxybenzenesulfonamide (Mte),4-methoxybenzenesulfonamide (Mbs), 2,4,6-trimethylbenzenesulfonamide(Mts), 2,6-dimethoxy-4-methylbenzenesulfonamide (iMds),2,2,5,7,8-pentamethylchroman-6-sulfonamide (Pmc), methanesulfonamide(Ms), β-trimethylsilylethanesulfonamide (SES), 9-anthracenesulfonamide,4-(4′,8′-dimethoxynaphthylmethyl)benzenesulfonamide (DNMBS),benzylsulfonamide, trifluoromethylsulfonamide, and phenacylsulfonamide.

Other nitrogen protecting groups include, but are not limited to,phenothiazinyl-(10)-acyl derivative, N′-p-toluenesulfonylaminoacylderivative, N′-phenylaminothioacyl derivative, N-benzoylphenylalanylderivative, N-acetylmethionine derivative,4,5-diphenyl-3-oxazolin-2-one, N-phthalimide, N-dithiasuccinimide (Dts),N-2,3-diphenylmaleimide, N-2,5-dimethylpyrrole,N-1,1,4,4-tetramethyldisilylazacyclopentane adduct (STABASE),5-substituted 1,3-dimethyl-1,3,5-triazacyclohexan-2-one, 5-substituted1,3-dibenzyl-1,3,5-triazacyclohexan-2-one, 1-substituted3,5-dinitro-4-pyridone, N-methylamine, N-allylamine,N-[2-(trimethylsilyl)ethoxy]methylamine (SEM), N-3-acetoxypropylamine,N-(1-isopropyl-4-nitro-2-oxo-3-pyroolin-3-yl)amine, quaternary ammoniumsalts, N-benzylamine, N-di(4-methoxyphenyl)methylamine,N-5-dibenzosuberylamine, N-triphenylmethylamine (Tr),N-[(4-methoxyphenyl)diphenylmethyl]amine (MMTr),N-9-phenylfluorenylamine (PhF),N-2,7-dichloro-9-fluorenylmethyleneamine, N-ferrocenylmethylamino (Fcm),N-2-picolylamino N′-oxide, N-1,1-dimethylthiomethyleneamine,N-benzylideneamine, N-p-methoxybenzylideneamine,N-diphenylmethyleneamine, N-[(2-pyridyl)mesityl]methyleneamine,N—(N′,N′-dimethylaminomethylene)amine, N,N′-isopropylidenediamine,N-p-nitrobenzylideneamine, N-salicylideneamine,N-5-chlorosalicylideneamine,N-(5-chloro-2-hydroxyphenyl)phenylmethyleneamine,N-cyclohexylideneamine, N-(5,5-dimethyl-3-oxo-1-cyclohexenyl)amine,N-borane derivative, N-diphenylborinic acid derivative,N-[phenyl(pentaacylchromium- or tungsten)acyl]amine, N-copper chelate,N-zinc chelate, N-nitroamine, N-nitrosoamine, amine N-oxide,diphenylphosphinamide (Dpp), dimethylthiophosphinamide (Mpt),diphenylthiophosphinamide (Ppt), dialkyl phosphoramidates, dibenzylphosphoramidate, diphenyl phosphoramidate, benzenesulfenamide,o-nitrobenzenesulfenamide (Nps), 2,4-dinitrobenzenesulfenamide,pentachlorobenzenesulfenamide, 2-nitro-4-methoxybenzenesulfenamide,triphenylmethylsulfenamide, and 3-nitropyridinesulfenamide (Npys).

In certain embodiments, the substituent present on an oxygen atom is anoxygen protecting group (also referred to as a hydroxyl protectinggroup). Oxygen protecting groups include, but are not limited to, —Raa,—N(Rbb)2, —C(═O)SRaa, —C(═O)Raa, —CO2Raa, —C(═O)N(Rbb)2, —C(═NRbb)Raa,—C(═NRbb)ORaa, —C(═NRbb)N(Rbb)2, —S(═O)Raa, —SO2Raa, Si(Raa)3, —P(Rcc)2,—P(Rcc)3, —P(═O)2Raa, —P(═O)(Raa)2, —P(═O)(ORcc)2, —P(═O)2N(Rbb)2, and—P(═O)(NRbb)2, wherein Raa, Rbb, and Rcc are as defined herein. Oxygenprotecting groups are well known in the art and include those describedin detail in Protecting Groups in Organic Synthesis, T. W. Greene and P.G. M. Wuts, 3rd edition, John Wiley & Sons, 1999, incorporated herein byreference.

Exemplary oxygen protecting groups include, but are not limited to,methyl, methoxylmethyl (MOM), methylthiomethyl (MTM), t-butylthiomethyl,(phenyldimethylsilyl)methoxymethyl (SMOM), benzyloxymethyl (BOM),p-methoxybenzyloxymethyl (PMBM), (4-methoxyphenoxy)methyl (p-AOM),guaiacolmethyl (GUM), t-butoxymethyl, 4-pentenyloxymethyl (POM),siloxymethyl, 2-methoxyethoxymethyl (MEM), 2,2,2-trichloroethoxymethyl,bis(2-chloroethoxy)methyl, 2-(trimethylsilyl)ethoxymethyl (SEMOR),tetrahydropyranyl (THP), 3-bromotetrahydropyranyl,tetrahydrothiopyranyl, 1-methoxycyclohexyl, 4-methoxytetrahydropyranyl(MTHP), 4-methoxytetrahydrothiopyranyl, 4-methoxytetrahydrothiopyranylS,S-dioxide, 1-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-yl(CTMP), 1,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl,2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl,1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 1-methyl-1-methoxyethyl,1-methyl-1-benzyloxyethyl, 1-methyl-1-benzyloxy-2-fluoroethyl,2,2,2-trichloroethyl, 2-trimethylsilylethyl, 2-(phenylselenyl)ethyl,t-butyl, allyl, p-chlorophenyl, p-methoxyphenyl, 2,4-dinitrophenyl,benzyl (Bn), p-methoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl,p-nitrobenzyl, p-halobenzyl, 2,6-dichlorobenzyl, p-cyanobenzyl,p-phenylbenzyl, 2-picolyl, 4-picolyl, 3-methyl-2-picolyl N-oxido,diphenylmethyl, p,p′-dinitrobenzhydryl, 5-dibenzosuberyl,triphenylmethyl, α-naphthyldiphenylmethyl,p-methoxyphenyldiphenylmethyl, di(p-methoxyphenyl)phenylmethyl,tri(p-methoxyphenyl)methyl, 4-(4′-bromophenacyloxyphenyl)diphenylmethyl,4,4′,4″-tris(4,5-dichlorophthalimidophenyl)methyl,4,4′,4″-tris(levulinoyloxyphenyl)methyl,4,4′,4″-tris(benzoyloxyphenyl)methyl,3-(imidazol-1-yl)bis(4′,4″-dimethoxyphenyl)methyl,1,1-bis(4-methoxyphenyl)-1′-pyrenylmethyl, 9-anthryl,9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl,1,3-benzodisulfuran-2-yl, benzisothiazolyl S,S-dioxido, trimethylsilyl(TMS), triethylsilyl (TES), triisopropylsilyl (TIPS),dimethylisopropylsilyl (IPDMS), diethylisopropylsilyl (DEIPS),dimethylthexylsilyl, t-butyldimethylsilyl (TBDMS), t-butyldiphenylsilyl(TBDPS), tribenzylsilyl, tri-p-xylylsilyl, triphenylsilyl,diphenylmethylsilyl (DPMS), t-butylmethoxyphenylsilyl (TBMPS), formate,benzoylformate, acetate, chloroacetate, dichloroacetate,trichloroacetate, trifluoroacetate, methoxyacetate,triphenylmethoxyacetate, phenoxyacetate, p-chlorophenoxyacetate,3-phenylpropionate, 4-oxopentanoate (levulinate),4,4-(ethylenedithio)pentanoate (levulinoyldithioacetal), pivaloate,adamantoate, crotonate, 4-methoxycrotonate, benzoate, p-phenylbenzoate,2,4,6-trimethylbenzoate (mesitoate), alkyl methyl carbonate,9-fluorenylmethyl carbonate (Fmoc), alkyl ethyl carbonate, alkyl2,2,2-trichloroethyl carbonate (Troc), 2-(trimethylsilyl)ethyl carbonate(TMSEC), 2-(phenylsulfonyl) ethyl carbonate (Psec),2-(triphenylphosphonio) ethyl carbonate (Peoc), alkyl isobutylcarbonate, alkyl vinyl carbonate alkyl allyl carbonate, alkylp-nitrophenyl carbonate, alkyl benzyl carbonate, alkyl p-methoxybenzylcarbonate, alkyl 3,4-dimethoxybenzyl carbonate, alkyl o-nitrobenzylcarbonate, alkyl p-nitrobenzyl carbonate, alkyl S-benzyl thiocarbonate,4-ethoxy-1-naphthyl carbonate, methyl dithiocarbonate, 2-iodobenzoate,4-azidobutyrate, 4-nitro-4-methylpentanoate, o-(dibromomethyl)benzoate,2-formylbenzenesulfonate, 2-(methylthiomethoxy)ethyl,4-(methylthiomethoxy)butyrate, 2-(methylthiomethoxymethyl)benzoate,2,6-dichloro-4-methylphenoxyacetate,2,6-dichloro-4-(1,1,3,3-tetramethylbutyl)phenoxyacetate,2,4-bis(1,1-dimethylpropyl)phenoxyacetate, chlorodiphenylacetate,isobutyrate, monosuccinate, (E)-2-methyl-2-butenoate,o-(methoxyacyl)benzoate, α-naphthoate, nitrate, alkylN,N,N′,N′-tetramethylphosphorodiamidate, alkyl N-phenylcarbamate,borate, dimethylphosphinothioyl, alkyl 2,4-dinitrophenylsulfenate,sulfate, methanesulfonate (mesylate), benzylsulfonate, and tosylate(Ts).

In certain embodiments, the substituent present on an sulfur atom is ansulfur protecting group (also referred to as a thiol protecting group).Sulfur protecting groups include, but are not limited to, —Raa,—N(Rbb)2, —C(═O)SRaa, —C(═O)Raa, —CO2Raa, C(═O)N(Rbb)2, —C(═NRbb)Raa,—C(═NRbb)ORaa, —C(═NRbb)N(Rbb)2, —S(═O)Raa, —SO2Raa, —Si(Raa)3,—P(Rcc)2, —P(Rcc)3, —P(═O)2Raa, —P(═O)(Raa)2, —P(═O)(ORcc)2,—P(═O)2N(Rbb)2, and —P(═O)(NRbb)2, wherein Raa, Rbb, and Rcc are asdefined herein. Sulfur protecting groups are well known in the art andinclude those described in detail in Protecting Groups in OrganicSynthesis, T. W. Greene and P. G. M. Wuts, 3rd edition, John Wiley &Sons, 1999, incorporated herein by reference.

As used herein, a “leaving group” is an art-understood term referring toa molecular fragment that departs with a pair of electrons inheterolytic bond cleavage, wherein the molecular fragment is an anion orneutral molecule. See, for example, Smith, March's Advanced OrganicChemistry 6th ed. (501-502). Exemplary leaving groups include, but arenot limited to, halo (e.g., chloro, bromo, iodo) and sulfonylsubstituted hydroxyl groups (e.g., tosyl, mesyl, besyl).

Additional Definitions

Animal: As used herein, the term “animal” refers to any member of theanimal kingdom. In some embodiments, “animal” refers to humans, at anystage of development. In some embodiments, “animal” refers to non-humananimals, at any stage of development. In certain embodiments, thenon-human animal is a mammal (e.g., a rodent, a mouse, a rat, a rabbit,a monkey, a dog, a cat, a sheep, cattle, a primate, and/or a pig). Insome embodiments, animals include, but are not limited to, mammals,birds, reptiles, amphibians, fish, insects, and/or worms. In someembodiments, an animal may be a transgenic animal,genetically-engineered animal, and/or a clone.

Approximately or about: As used herein, the term “approximately” or“about,” as applied to one or more values of interest, refers to a valuethat is similar to a stated reference value. In certain embodiments, theterm “approximately” or “about” refers to a range of values that fallwithin 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%,8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greaterthan or less than) of the stated reference value unless otherwise statedor otherwise evident from the context (except where such number wouldexceed 100% of a possible value).

Delivery: As used herein, the term “delivery” encompasses both local andsystemic delivery. For example, delivery of mRNA encompasses situationsin which an mRNA is delivered to a target tissue and the encoded proteinis expressed and retained within the target tissue (also referred to as“local distribution” or “local delivery”), and situations in which anmRNA is delivered to a target tissue and the encoded protein isexpressed and secreted into patient's circulation system (e.g., serum)and systematically distributed and taken up by other tissues (alsoreferred to as “systemic distribution” or “systemic delivery).

Expression: As used herein, “expression” of a nucleic acid sequencerefers to translation of an mRNA into a polypeptide, assemble multiplepolypeptides (e.g., heavy chain or light chain of antibody) into anintact protein (e.g., antibody) and/or post-translational modificationof a polypeptide or fully assembled protein (e.g., antibody). In thisapplication, the terms “expression” and “production,” and grammaticalequivalent, are used inter-changeably.

Improve, increase, or reduce: As used herein, the terms “improve,”“increase” or “reduce,” or grammatical equivalents, indicate values thatare relative to a baseline measurement, such as a measurement in thesame individual prior to initiation of the treatment described herein,or a measurement in a control subject (or multiple control subject) inthe absence of the treatment described herein. A “control subject” is asubject afflicted with the same form of disease as the subject beingtreated, who is about the same age as the subject being treated.

In Vitro: As used herein, the term “in vitro” refers to events thatoccur in an artificial environment, e.g., in a test tube or reactionvessel, in cell culture, etc., rather than within a multi-cellularorganism.

In Vivo: As used herein, the term “in vivo” refers to events that occurwithin a multi-cellular organism, such as a human and a non-humananimal. In the context of cell-based systems, the term may be used torefer to events that occur within a living cell (as opposed to, forexample, in vitro systems).

Isolated: As used herein, the term “isolated” refers to a substanceand/or entity that has been (1) separated from at least some of thecomponents with which it was associated when initially produced (whetherin nature and/or in an experimental setting), and/or (2) produced,prepared, and/or manufactured by the hand of man. Isolated substancesand/or entities may be separated from about 10%, about 20%, about 30%,about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%,about 98%, about 99%, or more than about 99% of the other componentswith which they were initially associated. In some embodiments, isolatedagents are about 80%, about 85%, about 90%, about 91%, about 92%, about93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%,or more than about 99% pure. As used herein, a substance is “pure” if itis substantially free of other components. As used herein, calculationof percent purity of isolated substances and/or entities should notinclude excipients (e.g., buffer, solvent, water, etc.).

Local distribution or delivery: As used herein, the terms “localdistribution,” “local delivery,” or grammatical equivalent, refer totissue specific delivery or distribution. Typically, local distributionor delivery requires a protein (e.g., enzyme) encoded by mRNAs betranslated and expressed intracellularly or with limited secretion thatavoids entering the patient's circulation system.

messenger RNA (mRNA): As used herein, the term “messenger RNA (mRNA)”refers to a polynucleotide that encodes at least one polypeptide. mRNAas used herein encompasses both modified and unmodified RNA. mRNA maycontain one or more coding and non-coding regions. mRNA can be purifiedfrom natural sources, produced using recombinant expression systems andoptionally purified, chemically synthesized, etc. Where appropriate,e.g., in the case of chemically synthesized molecules, mRNA can comprisenucleoside analogs such as analogs having chemically modified bases orsugars, backbone modifications, etc. An mRNA sequence is presented inthe 5′ to 3′ direction unless otherwise indicated. In some embodiments,an mRNA is or comprises natural nucleosides (e.g., adenosine, guanosine,cytidine, uridine); nucleoside analogs (e.g., 2-aminoadenosine,2-thiothymidine, inosine, pyrrolo-pyrimidine, 3-methyl adenosine,5-methylcytidine, C-5 propynyl-cytidine, C-5 propynyl-uridine,2-amino-adenosine, C5-bromouridine, C5-fluorouridine, C5-iodouridine,C5-propynyl-uridine, C5-propynyl-cytidine, C5-methylcytidine,2-aminoadenosine, 7-deazaadenosine, 7-deazaguanosine, 8-oxoadenosine,8-oxoguanosine, O(6)-methylguanine, and 2-thiocytidine); chemicallymodified bases; biologically modified bases (e.g., methylated bases);intercalated bases; modified sugars (e.g., 2′-fluororibose, ribose,2′-deoxyribose, arabinose, and hexose); and/or modified phosphate groups(e.g., phosphorothioates and 5′-N-phosphoramidite linkages).

Nucleic acid: As used herein, the term “nucleic acid,” in its broadestsense, refers to any compound and/or substance that is or can beincorporated into a polynucleotide chain. In some embodiments, a nucleicacid is a compound and/or substance that is or can be incorporated intoa polynucleotide chain via a phosphodiester linkage. In someembodiments, “nucleic acid” refers to individual nucleic acid residues(e.g., nucleotides and/or nucleosides). In some embodiments, “nucleicacid” refers to a polynucleotide chain comprising individual nucleicacid residues. In some embodiments, “nucleic acid” encompasses RNA suchas mRNA, siRNA, microRNA, as well as single and/or double-stranded DNAand/or cDNA.

Patient: As used herein, the term “patient” or “subject” refers to anyorganism to which a provided composition may be administered, e.g., forexperimental, diagnostic, prophylactic, cosmetic, and/or therapeuticpurposes. Typical patients include animals (e.g., mammals such as mice,rats, rabbits, non-human primates, and/or humans). In some embodiments,a patient is a human. A human includes pre and post natal forms.

Pharmaceutically acceptable: The term “pharmaceutically acceptable” asused herein, refers to substances that, within the scope of soundmedical judgment, are suitable for use in contact with the tissues ofhuman beings and animals without excessive toxicity, irritation,allergic response, or other problem or complication, commensurate with areasonable benefit/risk ratio.

Polymer: As used herein, a “polymer” refers to a compound comprised ofat least 3 (e.g., at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 100,etc.) repeating covalently bound structural units.

Salt: As used herein, the term “salt” or “pharmaceutically acceptablesalt” refers to those salts which are, within the scope of sound medicaljudgment, suitable for use in contact with the tissues of humans andlower animals without undue toxicity, irritation, allergic response andthe like, and are commensurate with a reasonable benefit/risk ratio.Pharmaceutically acceptable salts are well known in the art. Forexample, S. M. Berge et al., describes pharmaceutically acceptable saltsin detail in J. Pharmaceutical Sciences (1977) 66:1-19. Pharmaceuticallyacceptable salts of the compounds of this invention include thosederived from suitable inorganic and organic acids and bases. Examples ofpharmaceutically acceptable, nontoxic acid addition salts are salts ofan amino group formed with inorganic acids such as hydrochloric acid,hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid orwith organic acids such as acetic acid, oxalic acid, maleic acid,tartaric acid, citric acid, succinic acid or malonic acid or by usingother methods used in the art such as ion exchange. Otherpharmaceutically acceptable salts include adipate, alginate, ascorbate,aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate,camphorate, camphorsulfonate, citrate, cyclopentanepropionate.digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate,glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate,hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate,lactate, laurate, lauryl sulfate, malate, maleate, malonate,methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate,oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate,phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate,tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts,and the like. Salts derived from appropriate bases include alkali metal,alkaline earth metal, ammonium and N+(C1-4alkyl)4 salts. Representativealkali or alkaline earth metal salts include sodium, lithium, potassium,calcium, magnesium, and the like. Further pharmaceutically acceptablesalts include, when appropriate, nontoxic ammonium. quaternary ammonium,and amine cations formed using counterions such as halide, hydroxide,carboxylate, sulfate, phosphate, nitrate, sulfonate and aryl sulfonate.Further pharmaceutically acceptable salts include salts formed from thequaternization of an amine using an appropriate electrophile, e.g., analkyl halide, to form a quarternized alkylated amino salt.

Systemic distribution or delivery: As used herein, the terms “systemicdistribution,” “systemic delivery,” or grammatical equivalent, refer toa delivery or distribution mechanism or approach that affect the entirebody or an entire organism. Typically, systemic distribution or deliveryis accomplished via body's circulation system, e.g., blood stream.Compared to the definition of “local distribution or delivery.”

Subject: As used herein, the term “subject” refers to a human or anynon-human animal (e.g., mouse, rat, rabbit, dog, cat, cattle, swine,sheep, horse or primate). A human includes pre- and post-natal forms. Inmany embodiments, a subject is a human being. A subject can be apatient, which refers to a human presenting to a medical provider fordiagnosis or treatment of a disease. The term “subject” is used hereininterchangeably with “individual” or “patient.” A subject can beafflicted with or is susceptible to a disease or disorder but may or maynot display symptoms of the disease or disorder.

Substantially: As used herein, the term “substantially” refers to thequalitative condition of exhibiting total or near-total extent or degreeof a characteristic or property of interest. One of ordinary skill inthe biological arts will understand that biological and chemicalphenomena rarely, if ever, go to completion and/or proceed tocompleteness or achieve or avoid an absolute result. The term“substantially” is therefore used herein to capture the potential lackof completeness inherent in many biological and chemical phenomena.

Target tissues: As used herein, the term “target tissues” refers to anytissue that is affected by a disease to be treated. In some embodiments,target tissues include those tissues that display disease-associatedpathology, symptom, or feature.

DETAILED DESCRIPTION

The present invention provides, among other things, a novel class ofbiodegradable lipid compounds for improved in vivo delivery oftherapeutic agents, such as nucleic acids. In particular, abiodegradable compound described herein may be used to as a cationiclipid, together with other non-cationic lipids, to formulate a lipidbased nanoparticle (e.g., liposome) for encapsulating therapeuticagents, such as nucleic acids (e.g., DNA, siRNA, mRNA, microRNA) fortherapeutic use.

Biodegradable Compounds

In some embodiments, a biodegradable compound according to the inventionhas a structure of formula I:

or a pharmaceutically acceptable salt thereof,

wherein:

-   -   each instance of X is independently O or S;    -   each instance of Y is independently O or S;    -   each instance of R¹ is independently hydrogen, optionally        substituted alkyl, optionally substituted alkenyl, optionally        substituted alkynyl, optionally substituted carbocyclyl,        optionally substituted heterocyclyl, optionally substituted        aryl, optionally substituted heteroaryl, halogen, —OR^(A1),        —N(R^(A1))₂, —SR^(A1), or a group of formula (iv):

-   -   L is an optionally substituted alkylene, optionally substituted        alkenylene, optionally substituted alkynylene, optionally        substituted heteroalkylene, optionally substituted        heteroalkenylene, optionally substituted heteroalkynylene,        optionally substituted carbocyclylene, optionally substituted        heterocyclylene, optionally substituted arylene, or optionally        substituted heteroarylene, or combination thereof, and    -   each of R⁶ and R⁷ is independently hydrogen, optionally        substituted alkyl, optionally substituted alkenyl, optionally        substituted alkynyl, optionally substituted carbocyclyl,        optionally substituted heterocyclyl, optionally substituted        aryl, optionally substituted heteroaryl, a nitrogen protecting        group, or a group of formula (i), (ii) or (iii);    -   Formulae (i), (ii), and (iii) are:

-   -   each instance of R′ is independently hydrogen or optionally        substituted alkyl;    -   X′ is O or S, or NR^(X);    -   R^(X) is hydrogen, optionally substituted alkyl, optionally        substituted alkenyl, optionally substituted alkynyl, optionally        substituted carbocyclyl, optionally substituted heterocyclyl,        optionally substituted aryl, optionally substituted heteroaryl,        or a nitrogen protecting group;    -   Y′ is O, S, or NR^(Y);    -   R^(Y) is hydrogen, optionally substituted alkyl, optionally        substituted alkenyl, optionally substituted alkynyl, optionally        substituted carbocyclyl, optionally substituted heterocyclyl,        optionally substituted aryl, optionally substituted heteroaryl,        or a nitrogen protecting group;    -   R^(P) is hydrogen, optionally substituted alkyl, optionally        substituted alkenyl, optionally substituted alkynyl, optionally        substituted carbocyclyl, optionally substituted heterocyclyl,        optionally substituted aryl, optionally substituted heteroaryl,        an oxygen protecting group when attached to an oxygen atom, a        sulfur protecting group when attached to a sulfur atom, or a        nitrogen protecting group when attached to a nitrogen atom;    -   R^(L) is optionally substituted C₁₋₅₀ alkyl, optionally        substituted C₂₋₅₀ alkenyl, optionally substituted C₂₋₅₀ alkynyl,        optionally substituted heteroC₁₋₅₀ alkyl, optionally substituted        heteroC₂₋₅₀ alkenyl, optionally substituted heteroC₂₋₅₀ alkynyl,        or a polymer;    -   and    -   each occurrence of R^(A1) is independently hydrogen, optionally        substituted alkyl, optionally substituted alkenyl, optionally        substituted alkynyl, optionally substituted carbocyclyl,        optionally substituted heterocyclyl, optionally substituted        aryl, optionally substituted heteroaryl, an oxygen protecting        group when attached to an oxygen atom, a sulfur protecting group        when attached to an sulfur atom, a nitrogen protecting group        when attached to a nitrogen atom, or two R^(A1) groups, together        with the nitrogen atom to which they are attached, are joined to        form an optionally substituted heterocyclic or optionally        substituted heteroaryl ring.

In certain embodiments, a group of formula (i) represents a group offormula (i-a) or a group of formula (i-b):

wherein each variable is independently as defined above and describedherein. In some embodiments, a group of formula (i) is a group offormula (i-a). In some embodiments, a group of formula (i) is a group offormula (i-b).

In some embodiments, at least one instance of R¹ is a group of formula(iv). In some embodiments, at least one instance of R¹ is a group offormula (iv), wherein at least one of R⁶ and R⁷ is a group of formula(i), (ii) or (iii). In some embodiments, at least one instance of R¹ isa group of formula (iv), wherein each of R⁶ and R⁷ is independently agroup of formula (i), (ii) or (iii).

In some embodiments, each R¹ is independently a group of formula (iv).In some embodiments, each R¹ is independently a group of formula (iv),wherein at least one of R⁶ and R⁷ is a group of formula (i), (ii) or(iii). In some embodiments, each R¹ is independently a group of formula(iv), wherein each of R⁶ and R⁷ is independently a group of formula (i),(ii) or (iii). In some embodiments, each R¹ is independently a group offormula (iv), wherein each of R⁶ and R⁷ is independently a group offormula (i). In some embodiments, each R¹ is independently a group offormula (iv), wherein each of R⁶ and R⁷ is independently a group offormula (ii). In some embodiments, each R¹ is independently a group offormula (iv), wherein each of R⁶ and R⁷ is independently a group offormula (iii). In some embodiments, each R¹ is independently a group offormula (iv), wherein each of R⁶ and R⁷ is independently a group offormula (i-a). In some embodiments, each R¹ is independently a group offormula (iv), wherein each of R⁶ and R⁷ is independently a group offormula (i-b).

In some embodiments, each instance of R′ is hydrogen.

In some embodiments, L is an optionally substituted alkylene.

In some embodiments, a group of formula (iv) is of formula

wherein q is an integer between 1 and 50, inclusive, and each of R⁶ andR⁷ is independently as defined above and described herein.

In certain embodiments, at least one instance of Q is O. In certainembodiments, each instance of Q is O. In certain embodiments, at leastone instance of Q is S. In certain embodiments, each instance of Q is S.

In some embodiments, R^(Q) is hydrogen. In some embodiments, R^(Q) isoptionally substituted alkyl. In some embodiments, R^(Q) is optionallysubstituted alkenyl. In some embodiments, R^(Q) is optionallysubstituted alkynyl. In some embodiments, R^(Q) is carbocyclyl. In someembodiments, R^(Q) is optionally substituted heterocyclyl. In someembodiments, R^(Q) is optionally substituted aryl. In some embodiments,R^(Q) is optionally substituted heteroaryl. In some embodiments, R^(Q)is a nitrogen protecting group. In some embodiments, R^(Q) is a group offormula (i), (ii) or (iii). In some embodiments, R^(Q) is a group offormula (i). In some embodiments, R^(Q) is a group of formula (ii). Insome embodiments, R^(Q) is a group of formula (iii).

As generally defined above, each instance of R¹ is independentlyhydrogen, optionally substituted alkyl, optionally substituted alkenyl,optionally substituted alkynyl, optionally substituted carbocyclyl,optionally substituted heterocyclyl, optionally substituted aryl,optionally substituted heteroaryl, halogen, —OR, —N(R^(A1))₂, or—SR^(A1), or a group of formula (iv), wherein each of R^(A1) and formula(iv) is independently as defined above and described herein.

In some embodiments, one R¹ is not hydrogen. In some embodiments, bothof R¹ are not hydrogen.

In certain embodiments, R¹ is optionally substituted alkyl, optionallysubstituted alkenyl, optionally substituted alkynyl, optionallysubstituted carbocyclyl, optionally substituted heterocyclyl, optionallysubstituted aryl, or optionally substituted heteroaryl. In certainembodiments, at least one instance of R¹ is optionally substitutedalkyl, optionally substituted alkenyl, optionally substituted alkynyl,optionally substituted carbocyclyl, optionally substituted heterocyclyl,optionally substituted aryl, or optionally substituted heteroaryl.

In certain embodiments, R¹ is optionally substituted alkyl; e.g.,optionally substituted C₁₋₆alkyl, optionally substituted C₂₋₆alkyl,optionally substituted C₃₋₆alkyl, optionally substituted C₄₋₆alkyl,optionally substituted C₄₋₅alkyl, or optionally substituted C₃₋₄alkyl.In certain embodiments, at least one instance of R¹ is optionallysubstituted alkyl; e.g., optionally substituted C₁₋₆alkyl, optionallysubstituted C₂₋₆alkyl, optionally substituted C₃₋₆alkyl, optionallysubstituted C₄₋₆alkyl, optionally substituted C₄₋₅alkyl, or optionallysubstituted C₃₋₄alkyl.

In certain embodiments, R¹ is optionally substituted alkenyl, e.g.,optionally substituted C₂₋₆alkenyl, optionally substituted C₃₋₆alkenyl,optionally substituted C₄₋₆alkenyl, optionally substituted C₄₋₅alkenyl,or optionally substituted C₃₋₄alkenyl. In certain embodiments, at leastone instance of R¹ is optionally substituted alkenyl, e.g., optionallysubstituted C₂₋₆alkenyl, optionally substituted C₃₋₆alkenyl, optionallysubstituted C₄₋₆alkenyl, optionally substituted C₄₋₅alkenyl, oroptionally substituted C₃₋₄alkenyl.

In certain embodiments, R¹ is optionally substituted alkynyl, e.g.,optionally substituted C₂₋₆alkynyl, optionally substituted C₃₋₆alkynyl,optionally substituted C₄₋₆alkynyl, optionally substituted C₄₋₅alkynyl,or optionally substituted C₃₋₄alkynyl. In certain embodiments, at leastone instance of R¹ is optionally substituted alkynyl, e.g., optionallysubstituted C₂₋₆alkynyl, optionally substituted C₃₋₆alkynyl, optionallysubstituted C₄₋₆alkynyl, optionally substituted C₄₋₅alkynyl, oroptionally substituted C₃₋₄alkynyl.

In certain embodiments, R¹ is optionally substituted carbocyclyl, e.g.,optionally substituted C₃₋₁₀ carbocyclyl, optionally substituted C₅₋₈carbocyclyl, optionally substituted C₅₋₆ carbocyclyl, optionallysubstituted C₅ carbocyclyl, or optionally substituted C₆ carbocyclyl. Incertain embodiments, at least one instance of R¹ is optionallysubstituted carbocyclyl, e.g., optionally substituted C₃₋₁₀ carbocyclyl,optionally substituted C₅₋₈ carbocyclyl, optionally substituted C₅₋₆carbocyclyl, optionally substituted C₅ carbocyclyl, or optionallysubstituted C₆ carbocyclyl.

In some embodiments, R¹ is optionally substituted heterocyclyl, e.g.,optionally substituted 3-14 membered heterocyclyl, optionallysubstituted 3-10 membered heterocyclyl, optionally substituted 5-8membered heterocyclyl, optionally substituted 5-6 membered heterocyclyl,optionally substituted 5-membered heterocyclyl, or optionallysubstituted 6-membered heterocyclyl. In certain embodiments, at leastone instance of R¹ is optionally substituted heterocyclyl, e.g.,optionally substituted 3-14 membered heterocyclyl, optionallysubstituted 3-10 membered heterocyclyl, optionally substituted 5-8membered heterocyclyl, optionally substituted 5-6 membered heterocyclyl,optionally substituted 5-membered heterocyclyl, or optionallysubstituted 6-membered heterocyclyl.

In some embodiments, R¹ is optionally substituted aryl. In someembodiments, R¹ is optionally substituted phenyl. In some embodiments,R¹ is phenyl. In some embodiments, R¹ is substituted phenyl. In certainembodiments, at least one instance of R¹ is optionally substituted aryl,e.g., optionally substituted phenyl.

In some embodiments, R¹ is optionally substituted heteroaryl, e.g.,optionally substituted 5-14 membered heteroaryl, optionally substituted5-10 membered heteroaryl, optionally substituted 5-6 memberedheteroaryl, optionally substituted 5 membered heteroaryl, or optionallysubstituted 6 membered heteroaryl. In certain embodiments, at least oneinstance of R¹ is optionally substituted heteroaryl, e.g., optionallysubstituted 5-14 membered heteroaryl, optionally substituted 5-10membered heteroaryl, optionally substituted 5-6 membered heteroaryl,optionally substituted 5 membered heteroaryl, or optionally substituted6 membered heteroaryl.

In some embodiments, R¹ is halogen. In some embodiments, R¹ is —F. Insome embodiments, R¹ is —Cl. In some embodiments, R¹ is —Br. In someembodiments, R¹ is —I.

In some embodiments, R¹ is —OR^(A1), wherein R^(A1) is as defined aboveand described herein. In some embodiments, R¹ is —N(R^(A1))₂, whereineach R^(A1) is independently as defined above and described herein. Insome embodiments, R¹ is —SR^(A1), wherein R^(A1) is as defined above anddescribed herein.

In some embodiments, an R¹ alkyl, alkenyl, alkynyl, carbocyclyl,heterocyclyl, aryl, or heteroaryl group may be substituted. In someembodiments, an R¹ alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl,aryl, or heteroaryl group may be substituted with an optionallysubstituted amino group. In some embodiments, an R¹ alkyl, alkenyl,alkynyl, carbocyclyl, heterocyclyl, aryl, or heteroaryl group may besubstituted with an optionally substituted hydroxyl group. In someembodiments, an R¹ alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl,aryl, or heteroaryl group may be substituted with an optionallysubstituted thiol group. In any of the above embodiments, an R¹ alkyl,alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, or heteroaryl groupmay be substituted, for example, with an optionally substituted aminogroup (e.g., —NR⁶R⁷), an optionally substituted hydroxyl group (e.g.,—OR⁶), an optionally substituted thiol group (e.g., —SR⁶), or with agroup of formula (i), (ii), or (iii), wherein each instance of R⁶ and R⁷is independently hydrogen, optionally substituted alkyl, optionallysubstituted alkenyl, optionally substituted alkynyl, optionallysubstituted carbocyclyl, optionally substituted heterocyclyl, optionallysubstituted aryl, optionally substituted heteroaryl, a nitrogenprotecting group when attached to a nitrogen atom, an oxygen protectinggroup when attached to an oxygen atom, and a sulfur protecting groupwhen attached to a sulfur atom, or a group of formula (i), (ii), or(iii).

In some embodiments, R¹ is an optionally substituted natural amino acidside chain. In some embodiments, R¹ is a natural amino acid side chain.In some embodiments, R¹ is an optionally substituted unnatural aminoacid side chain. In some embodiments, R¹ is an unnatural amino acid sidechain.

In certain embodiments, each instance of R¹ is the same. In certainembodiments, at least one R¹ group is different. In certain embodiments,each R¹ group is different.

In certain embodiments, R¹ is an alkyl, alkenyl, alkynyl, carbocyclyl,heterocyclyl, aryl, or heteroaryl group substituted with an amino groupof the formula —NR⁶R⁷.

In certain embodiments, R¹ is a group of formula (iv):

wherein:L is an optionally substituted alkylene, optionally substitutedalkenylene, optionally substituted alkynylene, optionally substitutedheteroalkylene, optionally substituted heteroalkenylene, optionallysubstituted heteroalkynylene, optionally substituted carbocyclylene,optionally substituted heterocyclylene, optionally substituted arylene,or optionally substituted heteroarylene, or combination thereof; andeach of R⁶ and R⁷ is independently hydrogen, optionally substitutedalkyl, optionally substituted alkenyl, optionally substituted alkynyl,optionally substituted carbocyclyl, optionally substituted heterocyclyl,optionally substituted aryl, optionally substituted heteroaryl, anitrogen protecting group, or a group of formula (i), (ii) or (iii):

wherein each of R′, Y′, R^(P), R^(L) and X′ is independently as definedabove and described herein.

In some embodiments, at least one instance of R¹ is an alkyl, alkenyl,alkynyl, carbocyclyl, heterocyclyl, aryl, or heteroaryl groupsubstituted with an amino group of the formula —NR⁶R⁷. In someembodiments, at least one instance of R¹ is a group of formula (iv). Insome embodiments, at least one instance of R¹ is a group of formula(iv), wherein at least one instance of R⁶ and R⁷ is a group of theformula (i), (ii) or (iii). In some embodiments, at least one instanceof R¹ is a group of formula (iv), wherein each instance of R⁶ and R⁷ isa group of the formula (i), (ii) or (iii). In some embodiments, at leastone instance of R¹ is a group of formula (iv), wherein each instance ofR⁶ and R⁷ is a group of the formula (i). In some embodiments, at leastone instance of R¹ is a group of formula (iv), wherein each instance ofR⁶ and R⁷ is a group of the formula (ii). In some embodiments, at leastone instance of R¹ is a group of formula (iv), wherein each instance ofR⁶ and R⁷ is a group of the formula (iii).

In some embodiments, each instance of R¹ is a group of formula (iv). Insome embodiments, each instance of R¹ is a group of formula (iv),wherein each instance of R⁶ and R⁷ is a group of the formula (i), (ii)or (iii). In some embodiments, each instance of R¹ is a group of formula(iv), wherein each instance of R⁶ and R⁷ is a group of the formula (i),(ii) or (iii). In some embodiments, each instance of R¹ is a group offormula (iv), wherein each instance of R⁶ and R⁷ is a group of theformula (i). In some embodiments, each instance of R¹ is a group offormula (iv), wherein each instance of R⁶ and R⁷ is a group of theformula (ii). In some embodiments, each instance of R¹ is a group offormula (iv), wherein each instance of R⁶ and R⁷ is a group of theformula (iii).

In certain embodiments, at least two instances of R¹ is a group offormula (iv). In certain embodiments, at least three instances of R¹ isa group of formula (iv). In certain embodiments, at least four instancesof R¹ is a group of formula (iv). In certain embodiments, at least fiveinstances of R¹ is a group of formula (iv). In certain embodiments, atleast six instances of R¹ is a group of formula (iv). In certainembodiments, at least seven instances of R¹ is a group of formula (iv).In certain embodiments, at least eight instances of R¹ is a group offormula (iv). In certain embodiments, at least nine instances of R¹ is agroup of formula (iv). In certain embodiments, each instance of R¹ is agroup of formula (iv).

In certain embodiments, L is an optionally substituted alkylene; e.g.,optionally substituted C₁₋₅₀alkylene, optionally substitutedC₁₋₄₀alkylene, optionally substituted C₁₋₃₀alkylene, optionallysubstituted C₁₋₂₀alkylene, optionally substituted C₄₋₂₀alkylene,optionally substituted C₆₋₂₀alkylene, optionally substitutedC₈₋₂₀alkylene, optionally substituted C₁₀₋₂₀alkylene, optionallysubstituted C₁₋₆alkylene, optionally substituted C₂₋₆alkylene,optionally substituted C₃₋₆alkylene, optionally substitutedC₄₋₆alkylene, optionally substituted C₄₋₅alkylene, or optionallysubstituted C₃₋₄alkylene. In some embodiments, L is optionallysubstituted C₁ alkylene. In some embodiments, L is optionallysubstituted C₂ alkylene. In some embodiments, L is optionallysubstituted C₃ alkylene. In some embodiments, L is optionallysubstituted C₄ alkylene. In some embodiments, L is optionallysubstituted C₅ alkylene. In some embodiments, L is optionallysubstituted C₆ alkylene. In some embodiments, L is optionallysubstituted C₇ alkylene. In some embodiments, L is optionallysubstituted C₈ alkylene. In some embodiments, L is optionallysubstituted C₉ alkylene. In some embodiments, L is optionallysubstituted C₁₀ alkylene. In some embodiments, L is —CH₂—. In someembodiments, L is —(CH₂)₂—. In some embodiments, L is —(CH₂)₃—. In someembodiments, L is —(CH₂)₄—. In some embodiments, L is —(CH₂)₅—. In someembodiments, L is —(CH₂)₆—. In some embodiments, L is —(CH₂)₇—. In someembodiments, L is —(CH₂)₈—. In some embodiments, L is —(CH₂)₉—. In someembodiments, L is —(CH₂)₁₀—.

In certain embodiments, L is an optionally substituted alkenylene, e.g.,optionally substituted C₂₋₅₀alkenylene, optionally substitutedC₂₋₄₀alkenylene, optionally substituted C₂₋₃₀alkenylene, optionallysubstituted C₂₋₂₀alkenylene, optionally substituted C₄₋₂₀alkenylene,optionally substituted C₆₋₂₀alkenylene, optionally substitutedC₈₋₂₀alkenylene, optionally substituted C₁₀₋₂₀alkenylene, optionallysubstituted C₂₋₆alkenylene, optionally substituted C₃₋₆alkenylene,optionally substituted C₄₋₆alkenylene, optionally substitutedC₄₋₅alkenylene, or optionally substituted C₃₋₄alkenylene.

In certain embodiments, L is an optionally substituted alkynylene, e.g.,optionally substituted C₂₋₅₀alkynylene, optionally substitutedC₂₋₄₀alkynylene, optionally substituted C₂₋₃₀alkynylene, optionallysubstituted C₂₋₂₀alkynylene, optionally substituted C₄₋₂₀alkynylene,optionally substituted C₆₋₂₀alkynylene, optionally substitutedC₈₋₂₀alkynylene, optionally substituted C₁₀₋₂₀alkynylene, optionallysubstituted C₂₋₆alkynylene, optionally substituted C₃₋₆alkynylene,optionally substituted C₄₋₆alkynylene, optionally substitutedC₄₋₅alkynylene, or optionally substituted C₃₋₄alkynylene.

In certain embodiments, L is an optionally substituted heteroalkylene;e.g., optionally substituted heteroC₁₋₅₀alkylene, optionally substitutedheteroC₁₋₄₀alkylene, optionally substituted heteroC₁₋₃₀alkylene,optionally substituted heteroC₁₋₂₀alkylene, optionally substitutedheteroC₄₋₂₀alkylene, optionally substituted heteroC₆₋₂₀alkylene,optionally substituted heteroC₈₋₂₀ alkylene, optionally substitutedheteroC₁₀₋₂₀alkylene, optionally substituted heteroC₁₋₆alkylene,optionally substituted heteroC₂₋₆alkylene, optionally substitutedheteroC₃₋₆alkylene, optionally substituted heteroC₄₋₆alkylene,optionally substituted heteroC₄₋₅alkylene, or optionally substitutedheteroC₃₋₄alkylene. In some embodiments, L is optionally substitutedheteroC₂alkylene. In some embodiments, L is optionally substitutedheteroC₃alkylene. In some embodiments, L is optionally substitutedheteroC₄alkylene. In some embodiments, L is optionally substitutedheteroC₅alkylene. In some embodiments, L is optionally substitutedheteroC₆alkylene. In some embodiments, L is optionally substitutedheteroC₇alkylene. In some embodiments, L is optionally substitutedheteroC₅alkylene. In some embodiments, L is optionally substitutedheteroC₉alkylene. In some embodiments, L is optionally substitutedheteroC₁₀alkylene.

In certain embodiments, L is an optionally substituted heteroalkenylene,e.g., optionally substituted heteroC₂₋₅₀alkenylene, optionallysubstituted heteroC₂₋₄₀alkenylene, optionally substitutedheteroC₂₋₃₀alkenylene, optionally substituted heteroC₂₋₂₀alkenylene,optionally substituted heteroC₄₋₂₀alkenylene, optionally substitutedheteroC₆₋₂₀alkenylene, optionally substituted heteroC₈₋₂₀alkenylene,optionally substituted heteroC₁₀₋₂₀alkenylene, optionally substitutedheteroC₂₋₆alkenylene, optionally substituted heteroC₃₋₆alkenylene,optionally substituted heteroC₄₋₆alkenylene, optionally substitutedheteroC₄₋₅alkenylene, or optionally substituted heteroC₃₋₄alkenylene.

In certain embodiments, L is an optionally substituted heteroalkynylene,e.g., optionally substituted heteroC₂₋₅₀alkynylene, optionallysubstituted heteroC₂₋₄₀alkynylene, optionally substitutedheteroC₂₋₃₀alkynylene, optionally substituted heteroC₂₋₂₀alkynylene,optionally substituted heteroC₄₋₂₀alkynylene, optionally substitutedheteroC₆₋₂₀alkynylene, optionally substituted heteroC₈₋₂₀alkynylene,optionally substituted heteroC₁₀₋₂₀alkynylene, optionally substitutedheteroC₂₋₆alkynylene, optionally substituted heteroC₃₋₆alkynylene,optionally substituted heteroC₄₋₆alkynylene, optionally substitutedheteroC₄₋₅alkynylene, or optionally substituted heteroC₃₋₄alkynylene.

In certain embodiments, L is an optionally substituted carbocyclylene,e.g., optionally substituted C₃₋₁₀carbocyclylene, optionally substitutedC₅₋₈carbocyclylene, optionally substituted C₅₋₆carbocyclylene,optionally substituted C₅carbocyclylene, or optionally substitutedC₆carbocyclylene.

In certain embodiments, L is an optionally substituted heterocyclylene,e.g., optionally substituted 3-14 membered heterocyclylene, optionallysubstituted 3-10 membered heterocyclylene, optionally substituted 5-8membered heterocyclylene, optionally substituted 5-6 memberedheterocyclylene, optionally substituted 5-membered heterocyclylene, oroptionally substituted 6-membered heterocyclylene.

In certain embodiments, L is an optionally substituted arylene, e.g.,optionally substituted phenylene. In some embodiments, L is optionallysubstituted phenylene. In some embodiments, L is substituted phenylene.In some embodiments, L is unsubstituted phenylene.

In certain embodiments, L is an optionally substituted heteroarylene,e.g., optionally substituted 5-14 membered heteroarylene, optionallysubstituted 5-10 membered heteroarylene, optionally substituted 5-6membered heteroarylene, optionally substituted 5-membered heteroarylene,or optionally substituted 6-membered heteroarylene.

In certain embodiments, wherein L is an optionally substituted alkylenegroup, the group of formula (iv) is a group of the formula

wherein q is an integer between 1 and 50, inclusive, and each of R⁶ andR⁷ is independently as defined above and described herein.

In certain embodiments, q is an integer between 1 and 40, inclusive. Incertain embodiments, q is an integer between 1 and 30, inclusive. Incertain embodiments, q is an integer between 1 and 20, inclusive. Incertain embodiments, q is an integer between 1 and 10, inclusive. Incertain embodiments, q is an integer between 4 and 20, inclusive. Incertain embodiments, q is an integer between 6 and 20, inclusive. Incertain embodiments, q is an integer between 2 and 10, inclusive. Incertain embodiments, q is an integer between 2 and 9, inclusive. Incertain embodiments, q is an integer between 2 and 8, inclusive. Incertain embodiments, q is an integer between 2 and 7, inclusive. Incertain embodiments, q is an integer between 2 and 6, inclusive. Incertain embodiments, q is an integer between 2 and 5, inclusive. Incertain embodiments, q is an integer between 2 and 4, inclusive. Incertain embodiments, q is an integer between 3 and 10, inclusive. Incertain embodiments, q is an integer between 3 and 8, inclusive. Incertain embodiments, q is an integer between 3 and 7, inclusive. Incertain embodiments, q is an integer between 3 and 6, inclusive. Incertain embodiments, q is an integer between 3 and 5, inclusive. Incertain embodiments, q is 3 or 4. In certain embodiments, q is aninteger between 3 and 9, inclusive. In certain embodiments, q is aninteger between 8 and 20, inclusive. In certain embodiments, q is 1. Incertain embodiments, q is 2. In certain embodiments, q is 3. In certainembodiments, q is 4. In certain embodiments, q is 5. In certainembodiments, q is 6. In certain embodiments, q is 7. In certainembodiments, q is 8. In certain embodiments, q is 9. In certainembodiments, q is 10.

As generally defined above, each R⁶ is independently selected from thegroup consisting of hydrogen, optionally substituted alkyl, optionallysubstituted alkenyl, optionally substituted alkynyl, optionallysubstituted carbocyclyl, optionally substituted heterocyclyl, optionallysubstituted aryl, optionally substituted heteroaryl, a nitrogenprotecting group, or a group of formula (i), (ii) or (iii).

In some embodiments, R⁶ is hydrogen.

In some embodiments, R⁶ is optionally substituted alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₅₀ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₄₀ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₃₀ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₂₀ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₉ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₈ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₇ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₆ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₅ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₄ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₃ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₂ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₁ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₀ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₉ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₈ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₇ alkyl. In someembodiments, R⁶ is optionally substituted C₂₋₆ alkyl.

In some embodiments, R⁶ is optionally substituted C₄₋₅₀ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₄₀ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₃₀ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₂₀ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₉ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₈ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₇ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₆ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₅ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₄ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₃ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₂ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₁ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₀ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₉ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₈ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₇ alkyl. In someembodiments, R⁶ is optionally substituted C₄₋₆ alkyl.

In some embodiments, R⁶ is optionally substituted C₆₋₅₀ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₄₀ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₃₀ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₂₀ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₉ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₈ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₇ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₆ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₅ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₄ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₃ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₂ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₁ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₀ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₉ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₈ alkyl. In someembodiments, R⁶ is optionally substituted C₆₋₇ alkyl.

In some embodiments, R⁶ is optionally substituted C₈₋₅₀ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₄₀ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₃₀ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₂₀ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₉ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₈ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₇ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₆ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₅ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₄ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₃ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₂ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₁ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₀ alkyl. In someembodiments, R⁶ is optionally substituted C₈₋₉ alkyl.

In some embodiments, R⁶ is optionally substituted C₉₋₅₀ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₄₀ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₃₀ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₂₀ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₉ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₈ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₇ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₆ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₅ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₄ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₃ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₂ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₁ alkyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₀ alkyl.

In some embodiments, R⁶ is optionally substituted C₁₀₋₅₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₄₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₃₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₂₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₉ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₈ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₇ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₆ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₅ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₄ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₃ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₂ alkyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₁ alkyl.

In some embodiments, R⁶ is optionally substituted C₁₁₋₅₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₄₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₃₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₂₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₉ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₈ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₇ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₆ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₅ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₄ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₃ alkyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₂ alkyl.

In some embodiments, R⁶ is optionally substituted C₁₂₋₅₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₄₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₃₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₂₀ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₉ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₈ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₇ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₆ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₅ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₄ alkyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₃ alkyl.

In some embodiments, R⁶ is optionally substituted C₆ alkyl. In someembodiments, R⁶ is optionally substituted C₇ alkyl. In some embodiments,R⁶ is optionally substituted C₈ alkyl. In some embodiments, R⁶ isoptionally substituted C₉ alkyl. In some embodiments, R⁶ is optionallysubstituted C₁₀ alkyl. In some embodiments, R⁶ is optionally substitutedC₁₁ alkyl. In some embodiments, R⁶ is optionally substituted C₁₂ alkyl.In some embodiments, R⁶ is optionally substituted C₁₃ alkyl. In someembodiments, R⁶ is optionally substituted C₁₄ alkyl. In someembodiments, R⁶ is optionally substituted C₁₅ alkyl. In someembodiments, R⁶ is optionally substituted C₁₆ alkyl. In someembodiments, R⁶ is optionally substituted C₁₇ alkyl. In someembodiments, R⁶ is optionally substituted C₁₈ alkyl. In someembodiments, R⁶ is optionally substituted C₁₉ alkyl. In someembodiments, R⁶ is optionally substituted C₂₀ alkyl.

In some embodiments, for example, in any of the above embodiments, R⁶ isa substituted alkyl group. In some embodiments, R⁶ is an unsubstitutedalkyl group. In some embodiments, R⁶ is an optionally substitutedstraight-chain alkyl group. In some embodiments, R⁶ is a substitutedstraight-chain alkyl group. In some embodiments, R⁶ is an unsubstitutedstraight-chain alkyl group. In some embodiments, R⁶ is an optionallysubstituted branched alkyl group. In some embodiments, R⁶ is asubstituted branched alkyl group. In some embodiments, R⁶ is anunsubstituted branched alkyl group.

In some embodiments, R⁶ is optionally substituted alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₅₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₄₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₃₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₂₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₅ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₄ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₃ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₂ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₁ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₋₆ alkenyl.

In some embodiments, R⁶ is optionally substituted C₄₋₅₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₄₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₃₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₂₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₅ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₄ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₃ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₂ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₁ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₄₋₆ alkenyl.

In some embodiments, R⁶ is optionally substituted C₆₋₅₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₄₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₃₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₂₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₅ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₄ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₃ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₂ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₁ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₆₋₇ alkenyl.

In some embodiments, R⁶ is optionally substituted C₈₋₅₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₄₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₃₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₂₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₅ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₄ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₃ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₂ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₁ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₈₋₉ alkenyl.

In some embodiments, R⁶ is optionally substituted C₉₋₅₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₄₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₃₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₂₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₅ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₄ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₃ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₂ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₁ alkenyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₀ alkenyl.

In some embodiments, R⁶ is optionally substituted C₁₀₋₅₀ alkenyl. Insome embodiments, R⁶ is optionally substituted C₁₀₋₄₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₃₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₂₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₅ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₄ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₃ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₂ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₁ alkenyl.

In some embodiments, R⁶ is optionally substituted C₁₁₋₅₀ alkenyl. Insome embodiments, R⁶ is optionally substituted C₁₁₋₄₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₃₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₂₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₅ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₄ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₃ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₂ alkenyl.

In some embodiments, R⁶ is optionally substituted C₁₂₋₅₀ alkenyl. Insome embodiments, R⁶ is optionally substituted C₁₂₋₄₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₃₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₂₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₅ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₄ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₃ alkenyl.

In some embodiments, R⁶ is optionally substituted C₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₀ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₁ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₂ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₃ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₄ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₅ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₆ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₇ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₈ alkenyl. In someembodiments, R⁶ is optionally substituted C₁₉ alkenyl. In someembodiments, R⁶ is optionally substituted C₂₀ alkenyl.

In some embodiments, for example, in any of the above embodiments, R⁶ isa substituted alkenyl group. In some embodiments, R⁶ is an unsubstitutedalkenyl group. In some embodiments, R⁶ is an optionally substitutedstraight-chain alkenyl group. In some embodiments, R⁶ is a substitutedstraight-chain alkenyl group. In some embodiments, R⁶ is anunsubstituted straight-chain alkenyl group. In some embodiments, R⁶ isan optionally substituted branched alkenyl group. In some embodiments,R⁶ is a substituted branched alkenyl group. In some embodiments, R⁶ isan unsubstituted branched alkenyl group.

In some embodiments, R⁶ is optionally substituted alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₅₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₄₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₃₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₂₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₄ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₃ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₂ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₁ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₁₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₋₆ alkynyl.

In some embodiments, R⁶ is optionally substituted C₄₋₅₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₄₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₃₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₂₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₄ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₃ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₂ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₁ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₁₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₄₋₆ alkynyl.

In some embodiments, R⁶ is optionally substituted C₆₋₅₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₄₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₃₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₂₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₄ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₃ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₂ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₁ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₁₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₆₋₇ alkynyl.

In some embodiments, R⁶ is optionally substituted C₈₋₅₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₄₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₃₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₂₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₄ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₃ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₂ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₁ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₁₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₈₋₉ alkynyl.

In some embodiments, R⁶ is optionally substituted C₉₋₅₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₄₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₃₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₂₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₄ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₃ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₂ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₁ alkynyl. In someembodiments, R⁶ is optionally substituted C₉₋₁₀ alkynyl.

In some embodiments, R⁶ is optionally substituted C₁₀₋₅₀ alkynyl. Insome embodiments, R⁶ is optionally substituted C₁₀₋₄₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₃₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₂₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₄ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₃ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₂ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀₋₁₁ alkynyl.

In some embodiments, R⁶ is optionally substituted C₁₁₋₅₀ alkynyl. Insome embodiments, R⁶ is optionally substituted C₁₁₋₄₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₃₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₂₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₄ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₃ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₁₋₁₂ alkynyl.

In some embodiments, R⁶ is optionally substituted C₁₂₋₅₀ alkynyl. Insome embodiments, R⁶ is optionally substituted C₁₂₋₄₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₃₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₂₀ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₄ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂₋₁₃ alkynyl.

In some embodiments, R⁶ is optionally substituted C₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₀ alkynyl. In someembodiments, R⁶ is optionally substituted C11 alkynyl. In someembodiments, R⁶ is optionally substituted C₁₂ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₃ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₄ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₅ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₆ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₇ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₈ alkynyl. In someembodiments, R⁶ is optionally substituted C₁₉ alkynyl. In someembodiments, R⁶ is optionally substituted C₂₀ alkynyl.

In some embodiments, for example, in any of the above embodiments, R⁶ isa substituted alkynyl group. In some embodiments, R⁶ is an unsubstitutedalkynyl group. In some embodiments, R⁶ is an optionally substitutedstraight-chain alkynyl group. In some embodiments, R⁶ is a substitutedstraight-chain alkynyl group. In some embodiments, R⁶ is anunsubstituted straight-chain alkynyl group. In some embodiments, R⁶ isan optionally substituted branched alkynyl group. In some embodiments,R⁶ is a substituted branched alkynyl group. In some embodiments, R⁶ isan unsubstituted branched alkynyl group.

In some embodiments, R⁶ is optionally substituted carbocyclyl. In someembodiments, R⁶ is optionally substituted heterocyclyl. In someembodiments, R⁶ is optionally substituted aryl. In some embodiments, R⁶is optionally substituted heteroaryl. In some embodiments, R⁶ is anitrogen protecting group.

In some embodiments, R⁶ is a group of formula (i). In some embodiments,R⁶ is a group of formula (i-a). In some embodiments, R⁶ is a group offormula

In some embodiments, R⁶ is a group of formula (i-b). In someembodiments, R⁶ is a group of formula (ii). In some embodiments, R⁶ is agroup of formula (iii).

In some embodiments, R⁶ is substituted with one or more hydroxyl groups.In some embodiments, R⁶ is substituted with one hydroxyl group. In someembodiments, R⁶ is substituted with one 2-hydroxyl group (C1 is thecarbon atom directly bonded to the nitrogen atom depicted in formula(iv)).

As generally defined above, each R⁷ is independently selected from thegroup consisting of hydrogen, optionally substituted alkyl, optionallysubstituted alkenyl, optionally substituted alkynyl, optionallysubstituted carbocyclyl, optionally substituted heterocyclyl, optionallysubstituted aryl, optionally substituted heteroaryl, a nitrogenprotecting group, or a group of formula (i), (ii) or (iii).

In some embodiments, R⁷ is hydrogen.

In some embodiments, R⁷ is optionally substituted alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₅₀ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₄₀ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₃₀ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₂₀ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₉ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₈ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₇ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₆ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₅ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₄ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₃ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₂ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₁ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₀ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₉ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₈ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₇ alkyl. In someembodiments, R⁷ is optionally substituted C₂₋₆ alkyl.

In some embodiments, R⁷ is optionally substituted C₄₋₅₀ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₄₀ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₃₀ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₂₀ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₉ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₈ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₇ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₆ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₅ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₄ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₃ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₂ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₁ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₀ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₉ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₈ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₇ alkyl. In someembodiments, R⁷ is optionally substituted C₄₋₆ alkyl.

In some embodiments, R⁷ is optionally substituted C₆₋₅₀ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₄₀ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₃₀ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₂₀ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₉ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₈ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₇ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₆ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₅ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₄ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₃ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₂ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₁ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₀ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₉ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₈ alkyl. In someembodiments, R⁷ is optionally substituted C₆₋₇ alkyl.

In some embodiments, R⁷ is optionally substituted C₈₋₅₀ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₄₀ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₃₀ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₂₀ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₉ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₈ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₇ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₆ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₅ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₄ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₃ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₂ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₁ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₀ alkyl. In someembodiments, R⁷ is optionally substituted C₈₋₉ alkyl.

In some embodiments, R⁷ is optionally substituted C₉₋₅₀ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₄₀ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₃₀ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₂₀ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₉ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₈ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₇ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₆ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₅ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₄ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₃ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₂ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₁ alkyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₀ alkyl.

In some embodiments, R⁷ is optionally substituted C₁₀₋₅₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₄₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₃₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₂₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₉ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₈ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₇ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₆ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₅ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₄ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₃ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₂ alkyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₁ alkyl.

In some embodiments, R⁷ is optionally substituted C₁₁₋₅₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₄₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₃₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₂₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₉ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₈ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₇ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₆ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₅ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₄ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₃ alkyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₂ alkyl.

In some embodiments, R⁷ is optionally substituted C₁₂₋₅₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₄₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₃₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₂₀ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₉ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₈ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₇ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₆ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₅ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₄ alkyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₃ alkyl.

In some embodiments, R⁷ is optionally substituted C₆ alkyl. In someembodiments, R⁷ is optionally substituted C₇ alkyl. In some embodiments,R⁷ is optionally substituted C₈ alkyl. In some embodiments, R⁷ isoptionally substituted C₉ alkyl. In some embodiments, R⁷ is optionallysubstituted C₁₀ alkyl. In some embodiments, R⁷ is optionally substitutedC₁₁ alkyl. In some embodiments, R⁷ is optionally substituted C₁₂ alkyl.In some embodiments, R⁷ is optionally substituted C₁₃ alkyl. In someembodiments, R⁷ is optionally substituted C₁₄ alkyl. In someembodiments, R⁷ is optionally substituted C₁₅ alkyl. In someembodiments, R⁷ is optionally substituted C₁₆ alkyl. In someembodiments, R⁷ is optionally substituted C₁₇ alkyl. In someembodiments, R⁷ is optionally substituted C₁₈ alkyl. In someembodiments, R⁷ is optionally substituted C₁₉ alkyl. In someembodiments, R⁷ is optionally substituted C₂₀ alkyl.

In some embodiments, for example, in any of the above embodiments, R⁷ isa substituted alkyl group. In some embodiments, R⁷ is an unsubstitutedalkyl group. In some embodiments, R⁷ is an optionally substitutedstraight-chain alkyl group. In some embodiments, R⁷ is a substitutedstraight-chain alkyl group. In some embodiments, R⁷ is an unsubstitutedstraight-chain alkyl group. In some embodiments, R⁷ is an optionallysubstituted branched alkyl group. In some embodiments, R⁷ is asubstituted branched alkyl group. In some embodiments, R⁷ is anunsubstituted branched alkyl group.

In some embodiments, R⁷ is optionally substituted alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₅₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₄₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₃₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₂₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₅ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₄ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₃ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₂ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₁ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₋₆ alkenyl.

In some embodiments, R⁷ is optionally substituted C₄₋₅₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₄₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₃₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₂₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₅ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₄ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₃ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₂ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₁ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₄₋₆ alkenyl.

In some embodiments, R⁷ is optionally substituted C₆₋₅₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₄₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₃₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₂₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₅ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₄ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₃ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₂ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₁ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₆₋₇ alkenyl.

In some embodiments, R⁷ is optionally substituted C₈₋₅₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₄₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₃₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₂₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₅ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₄ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₃ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₂ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₁ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₈₋₉ alkenyl.

In some embodiments, R⁷ is optionally substituted C₉₋₅₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₄₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₃₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₂₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₅ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₄ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₃ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₂ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₁ alkenyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₀ alkenyl.

In some embodiments, R⁷ is optionally substituted C₁₀₋₅₀ alkenyl. Insome embodiments, R⁷ is optionally substituted C₁₀₋₄₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₃₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₂₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₅ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₄ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₃ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₂ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₁ alkenyl.

In some embodiments, R⁷ is optionally substituted C₁₁₋₅₀ alkenyl. Insome embodiments, R⁷ is optionally substituted C₁₁₋₄₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₃₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₂₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₅ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₄ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₃ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₂ alkenyl.

In some embodiments, R⁷ is optionally substituted C₁₂₋₅₀ alkenyl. Insome embodiments, R⁷ is optionally substituted C₁₂₋₄₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₃₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₂₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₅ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₄ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₃ alkenyl.

In some embodiments, R⁷ is optionally substituted C₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₀ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₁ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₂ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₃ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₄ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₅ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₆ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₇ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₈ alkenyl. In someembodiments, R⁷ is optionally substituted C₁₉ alkenyl. In someembodiments, R⁷ is optionally substituted C₂₀ alkenyl.

In some embodiments, for example, in any of the above embodiments, R⁷ isa substituted alkenyl group. In some embodiments, R⁷ is an unsubstitutedalkenyl group. In some embodiments, R⁷ is an optionally substitutedstraight-chain alkenyl group. In some embodiments, R⁷ is a substitutedstraight-chain alkenyl group. In some embodiments, R⁷ is anunsubstituted straight-chain alkenyl group. In some embodiments, R⁷ isan optionally substituted branched alkenyl group. In some embodiments,R⁷ is a substituted branched alkenyl group. In some embodiments, R⁷ isan unsubstituted branched alkenyl group.

In some embodiments, R⁷ is optionally substituted alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₅₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₄₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₃₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₂₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₅ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₄ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₃ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₂ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₁ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₁₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₋₆ alkynyl.

In some embodiments, R⁷ is optionally substituted C₄₋₅₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₄₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₃₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₂₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₅ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₄ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₃ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₂ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₁ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₁₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₄₋₆ alkynyl.

In some embodiments, R⁷ is optionally substituted C₆₋₅₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₄₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₃₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₂₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₅ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₄ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₃ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₂ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₁ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₁₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₆₋₇ alkynyl.

In some embodiments, R⁷ is optionally substituted C₈₋₅₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₄₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₃₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₂₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₅ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₄ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₃ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₂ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₁ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₁₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₈₋₉ alkynyl.

In some embodiments, R⁷ is optionally substituted C₉₋₅₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₄₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₃₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₂₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₅ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₄ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₃ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₂ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₁ alkynyl. In someembodiments, R⁷ is optionally substituted C₉₋₁₀ alkynyl.

In some embodiments, R⁷ is optionally substituted C₁₀₋₅₀ alkynyl. Insome embodiments, R⁷ is optionally substituted C₁₀₋₄₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₃₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₂₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₅ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₄ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₃ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₂ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀₋₁₁ alkynyl.

In some embodiments, R⁷ is optionally substituted C₁₁₋₅₀ alkynyl. Insome embodiments, R⁷ is optionally substituted C₁₁₋₄₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₃₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₂₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₅ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₄ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₃ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₁₋₁₂ alkynyl.

In some embodiments, R⁷ is optionally substituted C₁₂₋₅₀ alkynyl. Insome embodiments, R⁷ is optionally substituted C₁₂₋₄₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₃₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₂₀ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₅ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₄ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂₋₁₃ alkynyl.

In some embodiments, R⁷ is optionally substituted C₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₀ alkynyl. In someembodiments, R⁷ is optionally substituted C11 alkynyl. In someembodiments, R⁷ is optionally substituted C₁₂ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₃ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₄ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₅ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₆ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₇ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₈ alkynyl. In someembodiments, R⁷ is optionally substituted C₁₉ alkynyl. In someembodiments, R⁷ is optionally substituted C₂₀ alkynyl.

In some embodiments, for example, in any of the above embodiments, R⁷ isa substituted alkynyl group. In some embodiments, R⁷ is an unsubstitutedalkynyl group. In some embodiments, R⁷ is an optionally substitutedstraight-chain alkynyl group. In some embodiments, R⁷ is a substitutedstraight-chain alkynyl group. In some embodiments, R⁷ is anunsubstituted straight-chain alkynyl group. In some embodiments, R⁷ isan optionally substituted branched alkynyl group. In some embodiments,R⁷ is a substituted branched alkynyl group. In some embodiments, R⁷ isan unsubstituted branched alkynyl group.

In some embodiments, R⁷ is optionally substituted carbocyclyl. In someembodiments, R⁷ is optionally substituted heterocyclyl. In someembodiments, R⁷ is optionally substituted aryl. In some embodiments, R⁷is optionally substituted heteroaryl. In some embodiments, R⁷ is anitrogen protecting group.

In some embodiments, R⁷ is a group of formula (i). In some embodiments,R⁷ is a group of formula (i-a). In some embodiments, R⁷ is a group offormula

In some embodiments, R⁷ is a group of formula (i-b). In someembodiments, R⁷ is a group of formula (ii). In some embodiments, R⁷ is agroup of formula (iii).

In some embodiments, at least one instance of R⁶ and R⁷ is a group ofthe formula (i), (ii) or (iii). In some embodiments, each instance of R⁶and R⁷ is independently a group of the formula (i), (ii) or (iii). Insome embodiments, each instance of R⁶ and R⁷ is independently a group ofthe formula (i). In some embodiments, each instance of R⁶ and R⁷ isindependently a group of the formula (i-a). In some embodiments, eachinstance of R⁶ and R⁷ is independently a group of the formula (i-b). Insome embodiments, each instance of R⁶ and R⁷ is independently a group ofthe formula (ii). In some embodiments, each instance of R⁶ and R⁷ isindependently a group of the formula (iii).

In some embodiments, R⁶ and R⁷ are the same. In some embodiments, R⁶ andR⁷ are different.

In certain embodiments, both R⁶ and R⁷ are hydrogen. In certainembodiments, R⁶ is hydrogen and R⁷ is a group of the formula (i), (ii),or (iii). In certain embodiments, R⁶ is hydrogen and R⁷ is a group ofthe formula (i). In certain embodiments, R⁶ is hydrogen and R⁷ is agroup of the formula (ii). In certain embodiments, R⁶ is hydrogen and R⁷is a group of the formula (iii). In certain embodiments, each of R⁶ andR⁷ is independently a group of the formula (i), (ii), or (iii). Incertain embodiments, each of R⁶ and R⁷ is independently a group of theformula (i). In certain embodiments, each of R⁶ and R⁷ is independentlya group of the formula (ii). In certain embodiments, each of R⁶ and R⁷is independently a group of the formula (iii). In certain embodiments,R⁶ and R⁷ are the same group, which is selected from formulas (i), (ii),and (iii). In some embodiments, R⁶ and R⁷ are the same group of formula(i). In some embodiments, R⁶ and R⁷ are the same group of formula (i-a).In some embodiments, R⁶ and R⁷ are the same group of formula (i-a1). Insome embodiments, R⁶ and R⁷ are the same group of formula (i-b).

In some embodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is as defined above and described herein. In someembodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₁₋₅₀alkyl, optionallysubstituted C₂₋₅₀alkenyl, optionally substituted C₂₋₅₀alkynyl,optionally substituted heteroC₁₋₅₀alkyl, optionally substitutedheteroC₂₋₅₀alkenyl, or optionally substituted heteroC₂₋₅₀alkynyl. Insome embodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₅₀alkyl, optionallysubstituted C₅₋₅₀alkenyl, optionally substituted C₅₋₅₀alkynyl,optionally substituted heteroC₅₋₅₀alkyl, optionally substitutedheteroC₅₋₅₀alkenyl, or optionally substituted heteroC₅₋₅₀alkynyl. Insome embodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₄₀alkyl, optionallysubstituted C₅₋₄₀alkenyl, optionally substituted C₅₋₄₀alkynyl,optionally substituted heteroC₅₋₄₀alkyl, optionally substitutedheteroC₅₋₄₀alkenyl, or optionally substituted heteroC₅₋₄₀alkynyl. Insome embodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₃₀alkyl, optionallysubstituted C₅₋₃₀alkenyl, optionally substituted C₅₋₃₀alkynyl,optionally substituted heteroC₅₋₃₀alkyl, optionally substitutedheteroC₅₋₃₀alkenyl, or optionally substituted heteroC₅₋₃₀alkynyl. Insome embodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₂₅alkyl, optionallysubstituted C₅₋₂₅alkenyl, optionally substituted C₅₋₂₅alkynyl,optionally substituted heteroC₅₋₂₅alkyl, optionally substitutedheteroC₅₋₂₅alkenyl, or optionally substituted heteroC₅₋₂₅alkynyl. Insome embodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₂₀alkyl, optionallysubstituted C₅₋₂₀alkenyl, optionally substituted C₅₋₂₀alkynyl,optionally substituted heteroC₅₋₂₀alkyl, optionally substitutedheteroC₅₋₂₀alkenyl, or optionally substituted heteroC₅₋₂₀alkynyl. Insome embodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₁₅alkyl, optionallysubstituted C₅₋₁₅alkenyl, optionally substituted C₅₋₁₅alkynyl,optionally substituted heteroC₅₋₁₅alkyl, optionally substitutedheteroC₅₋₁₅alkenyl, or optionally substituted heteroC₅₋₁₅alkynyl. Insome embodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅ alkyl, optionally substitutedC₅ alkenyl, optionally substituted C₅ alkynyl, optionally substitutedheteroC₅alkyl, optionally substituted heteroC₅alkenyl, or optionallysubstituted heteroC₅alkynyl. In some embodiments, R⁶ and R⁷ are the samegroup of formula

wherein R^(L) is optionally substituted C₆ alkyl, optionally substitutedC₆ alkenyl, optionally substituted C₆ alkynyl, optionally substitutedheteroC₆alkyl, optionally substituted heteroC₆alkenyl, or optionallysubstituted heteroC₆alkynyl. In some embodiments, R⁶ and R⁷ are the samegroup of formula

wherein R^(L) is optionally substituted C₇ alkyl, optionally substitutedC₇ alkenyl, optionally substituted C₇ alkynyl, optionally substitutedheteroC₇alkyl, optionally substituted heteroC₇alkenyl, or optionallysubstituted heteroC₇alkynyl. In some embodiments, R⁶ and R⁷ are the samegroup of formula

wherein R^(L) is optionally substituted C₈ alkyl, optionally substitutedC₈ alkenyl, optionally substituted C₈ alkynyl, optionally substitutedheteroC₈alkyl, optionally substituted heteroC₈alkenyl, or optionallysubstituted heteroC₈alkynyl. In some embodiments, R⁶ and R⁷ are the samegroup of formula

wherein R^(L) is optionally substituted C₉ alkyl, optionally substitutedC₉ alkenyl, optionally substituted C₉ alkynyl, optionally substitutedheteroC₉alkyl, optionally substituted heteroC₉alkenyl, or optionallysubstituted heteroC₉alkynyl. In some embodiments, R⁶ and R⁷ are the samegroup of formula

wherein R^(L) is optionally substituted C₁₀ alkyl, optionallysubstituted C₁₀ alkenyl, optionally substituted C₁₀ alkynyl, optionallysubstituted heteroC₁₀alkyl, optionally substituted heteroC₁₀alkenyl, oroptionally substituted heteroC₁₀alkynyl. In some embodiments, R⁶ and R⁷are the same group of formula

wherein R^(L) is optionally substituted C₁₁ alkyl, optionallysubstituted C₁₁ alkenyl, optionally substituted C₁₁ alkynyl, optionallysubstituted heteroC₁₁alkyl, optionally substituted heteroC₁₁alkenyl, oroptionally substituted heteroC₁₁alkynyl. In some embodiments, R⁶ and R⁷are the same group of formula

wherein R^(L) is optionally substituted C₁₂ alkyl, optionallysubstituted C₁₂ alkenyl, optionally substituted C₁₂ alkynyl, optionallysubstituted heteroC₁₂alkyl, optionally substituted heteroC₁₂alkenyl, oroptionally substituted heteroC₁₂alkynyl. In some embodiments, R⁶ and R⁷are the same group of formula

wherein R^(L) is optionally substituted C₁₃ alkyl, optionallysubstituted C₁₃ alkenyl, optionally substituted C₁₃ alkynyl, optionallysubstituted heteroC₁₃alkyl, optionally substituted heteroC₁₃alkenyl, oroptionally substituted heteroC₃alkynyl. In some embodiments, R⁶ and R⁷are the same group of formula

wherein R^(L) is optionally substituted C₁₄ alkyl, optionallysubstituted C₁₄ alkenyl, optionally substituted C₁₄ alkynyl, optionallysubstituted heteroC₁₄alkyl, optionally substituted heteroC₁₄alkenyl, oroptionally substituted heteroC₁₄alkynyl. In some embodiments, R⁶ and R⁷are the same group of formula

wherein R^(L) is optionally substituted C₁₅ alkyl, optionallysubstituted C₁₅ alkenyl, optionally substituted C₁₅ alkynyl, optionallysubstituted heteroC₁₅alkyl, optionally substituted heteroC₁₅alkenyl, oroptionally substituted heteroC₁₅alkynyl.

In some embodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is as defined above and described herein. In someembodiments, R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₁₋₅₀alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₅₀alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₄₀alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₃₀alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₂₅alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₂₀alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅₋₁₅alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₅ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₆ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₇ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₈ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₉ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₁₀ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₁₁ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₁₂ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₁₃ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₁₄ alkyl. In some embodiments,R⁶ and R⁷ are the same group of formula

wherein R^(L) is optionally substituted C₁₅ alkyl.

As generally defined above, each occurrence of R^(A1) is independentlyhydrogen, optionally substituted alkyl, optionally substituted alkenyl,optionally substituted alkynyl, optionally substituted carbocyclyl,optionally substituted heterocyclyl, optionally substituted aryl,optionally substituted heteroaryl, an oxygen protecting group whenattached to an oxygen atom, a sulfur protecting group when attached toan sulfur atom, a nitrogen protecting group when attached to a nitrogenatom, or two R^(A1) groups, together with the nitrogen atom to whichthey are attached, are joined to form an optionally substitutedheterocyclic or optionally substituted heteroaryl ring.

In some embodiments, R^(A1) is hydrogen. In some embodiments, R^(A1) isoptionally substituted alkyl. In some embodiments, R^(A1) is optionallysubstituted alkenyl. In some embodiments, R^(A1) is optionallysubstituted alkynyl. In some embodiments, R^(A1) is optionallysubstituted carbocyclyl. In some embodiments, R^(A1) is optionallysubstituted heterocyclyl. In some embodiments, R^(A1) is optionallysubstituted aryl. In some embodiments, R^(A1) is optionally substitutedheteroaryl. In some embodiments, R^(A1) is an oxygen protecting groupwhen attached to an oxygen atom. In some embodiments, R^(A1) is a sulfurprotecting group when attached to a sulfur atom. In some embodiments,R^(A1) is a nitrogen protecting group when attached to a nitrogen atom.In some embodiments, two R^(A1) groups, together with the nitrogen atomto which they are attached, are joined to form an optionally substitutedheterocyclic or optionally substituted heteroaryl ring.

As generally defined above, each instance of R′ is independentlyhydrogen or optionally substituted alkyl. In some embodiments, R′ ishydrogen. In some embodiments, R′ is substituted alkyl. In certainembodiments, at least one instance of R′ is hydrogen. In certainembodiments, at least two instances of R′ is hydrogen. In certainembodiments, each instance of R′ is hydrogen. In certain embodiments, atleast one instance of R′ is optionally substituted alkyl, e.g., methyl.In certain embodiments, at least two instances of R′ is optionallysubstituted alkyl, e.g., methyl. In some embodiments, at least oneinstance of R′ is hydrogen, and at least one instance of R′ isoptionally substituted alkyl. In certain embodiments, one instance of R′is optionally substituted alkyl, and the rest are hydrogen.

As generally defined above, X is O, S, or NR^(X). In some embodiments, Xis O. In some embodiments, X is S. In some embodiments, X is NR^(X),wherein R^(X) is as defined above and described herein.

As generally defined above, R^(X) is hydrogen, optionally substitutedalkyl, optionally substituted alkenyl, optionally substituted alkynyl,optionally substituted carbocyclyl, optionally substituted heterocyclyl,optionally substituted aryl, optionally substituted heteroaryl, or anitrogen protecting group. In some embodiments, R^(X) is hydrogen. Insome embodiments, R^(X) is optionally substituted alkyl. In someembodiments, R^(X) is optionally substituted alkenyl. In someembodiments, R^(X) is optionally substituted alkynyl. In someembodiments, R^(X) is optionally substituted carbocyclyl. In someembodiments, R^(X) is optionally substituted heterocyclyl. In someembodiments, R^(X) is optionally substituted aryl. In some embodiments,R^(X) is optionally substituted heteroaryl. In some embodiments, R^(X)is a nitrogen protecting group.

As generally defined above, Y is O, S, or NR^(Y). In some embodiments, Yis O. In some embodiments, Y is S. In some embodiments, Y is NR^(Y),wherein R^(Y) is as defined above and described herein.

As generally defined above, R^(Y) is hydrogen, optionally substitutedalkyl, optionally substituted alkenyl, optionally substituted alkynyl,optionally substituted carbocyclyl, optionally substituted heterocyclyl,optionally substituted aryl, optionally substituted heteroaryl, or anitrogen protecting group. In some embodiments, R^(Y) is hydrogen. Insome embodiments, R^(Y) is optionally substituted alkyl. In someembodiments, R^(Y) is optionally substituted alkenyl. In someembodiments, R^(Y) is optionally substituted alkynyl. In someembodiments, R^(Y) is optionally substituted carbocyclyl. In someembodiments, R^(Y) is optionally substituted heterocyclyl. In someembodiments, R^(Y) is optionally substituted aryl. In some embodiments,R^(Y) is optionally substituted heteroaryl. In some embodiments, R^(Y)is a nitrogen protecting group.

As generally defined above, R^(P) is hydrogen, optionally substitutedalkyl, optionally substituted alkenyl, optionally substituted alkynyl,optionally substituted carbocyclyl, optionally substituted heterocyclyl,optionally substituted aryl, optionally substituted heteroaryl, anoxygen protecting group when attached to an oxygen atom, a sulfurprotecting group when attached to a sulfur atom, or a nitrogenprotecting group when attached to a nitrogen atom. In some embodiments,R^(P) is hydrogen. In some embodiments, R^(P) is optionally substitutedalkyl. In some embodiments, R^(P) is optionally substituted alkenyl. Insome embodiments, R^(P) is optionally substituted alkynyl. In someembodiments, R^(P) is optionally substituted carbocyclyl. In someembodiments, R^(P) is optionally substituted heterocyclyl. In someembodiments, R^(P) is optionally substituted aryl. In some embodiments,R^(P) is optionally substituted heteroaryl. In some embodiments, R^(P)is an oxygen protecting group when attached to an oxygen atom. In someembodiments, R^(P) is a sulfur protecting group when attached to asulfur atom. In some embodiments, R^(P) is a nitrogen protecting groupwhen attached to a nitrogen atom.

As generally defined above, R^(L) is optionally substituted C₁₋₅₀ alkyl,optionally substituted C₂₋₅₀ alkenyl, optionally substituted C₂₋₅₀alkynyl, optionally substituted heteroC₁₋₅₀ alkyl, optionallysubstituted heteroC₂₋₅₀ alkenyl, optionally substituted heteroC₂₋₅₀alkynyl, or a polymer.

In some embodiments, R^(L) is optionally substituted C₁₋₅₀ alkyl. Insome embodiments, R^(L) is optionally substituted C₂₋₅₀ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₄₀ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₃₀ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₂₀ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₉ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₈ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₇ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₆ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₄ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₃ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₂ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₁ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₀ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₉ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₈ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₇ alkyl. In someembodiments, R^(L) is optionally substituted C₂₋₆ alkyl.

In some embodiments, R^(L) is optionally substituted C₄₋₅₀ alkyl. Insome embodiments, R^(L) is optionally substituted C₄₋₄₀ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₃₀ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₂₀ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₉ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₈ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₇ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₆ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₄ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₃ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₂ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₁ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₀ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₉ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₈ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₇ alkyl. In someembodiments, R^(L) is optionally substituted C₄₋₆ alkyl.

In some embodiments, R^(L) is optionally substituted C₆₋₅₀ alkyl. Insome embodiments, R^(L) is optionally substituted C₆₋₄₀ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₃₀ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₂₀ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₉ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₈ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₇ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₆ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₄ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₃ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₂ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₁ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₀ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₉ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₈ alkyl. In someembodiments, R^(L) is optionally substituted C₆₋₇ alkyl.

In some embodiments, R^(L) is optionally substituted C₈₋₅₀ alkyl. Insome embodiments, R^(L) is optionally substituted C₈₋₄₀ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₃₀ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₂₀ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₉ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₈ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₇ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₆ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₄ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₃ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₂ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₁ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₀ alkyl. In someembodiments, R^(L) is optionally substituted C₈₋₉ alkyl.

In some embodiments, R^(L) is optionally substituted C₉₋₅₀ alkyl. Insome embodiments, R^(L) is optionally substituted C₉₋₄₀ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₃₀ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₂₀ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₉ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₈ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₇ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₆ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₄ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₃ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₂ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₁ alkyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₀ alkyl.

In some embodiments, R^(L) is optionally substituted C₁₀₋₅₀ alkyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₄₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₃₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₂₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₁₉ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₁₇ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₁₆ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₁₄ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₁₃ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₁₂ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀₋₁₁ alkyl.

In some embodiments, R^(L) is optionally substituted C₁₁₋₅₀ alkyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₄₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₃₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₂₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₁₉ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₁₈ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₁₇ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₁₆ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₁₄ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₁₃ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁₋₁₂ alkyl.

In some embodiments, R^(L) is optionally substituted C₁₂₋₅₀ alkyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₄₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂₋₃₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂₋₂₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂₋₁₉ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂₋₁₈ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂₋₁₇ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂₋₁₆ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂₋₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂₋₁₄ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂₋₁₃ alkyl.

In some embodiments, R^(L) is optionally substituted C₆ alkyl. In someembodiments, R^(L) is optionally substituted C₇ alkyl. In someembodiments, R^(L) is optionally substituted C₈ alkyl. In someembodiments, R^(L) is optionally substituted C₉ alkyl. In someembodiments, R^(L) is optionally substituted C₁₀ alkyl. In someembodiments, R^(L) is optionally substituted C₁₁ alkyl. In someembodiments, R^(L) is optionally substituted C₁₂ alkyl. In someembodiments, R^(L) is optionally substituted C₁₃ alkyl. In someembodiments, R^(L) is optionally substituted C₁₄ alkyl. In someembodiments, R^(L) is optionally substituted C₁₅ alkyl. In someembodiments, R^(L) is optionally substituted C₁₆ alkyl. In someembodiments, R^(L) is optionally substituted C₁₇ alkyl. In someembodiments, R^(L) is optionally substituted C₁₈ alkyl. In someembodiments, R^(L) is optionally substituted C₁₉ alkyl. In someembodiments, R^(L) is optionally substituted C₂₀ alkyl.

In some embodiments, for example, in any of the above embodiments, R^(L)is a substituted alkyl group. In some embodiments, R^(L) is anunsubstituted alkyl group. In some embodiments, R^(L) is an optionallysubstituted straight-chain alkyl group. In some embodiments, R^(L) is asubstituted straight-chain alkyl group. In some embodiments, R^(L) is anunsubstituted straight-chain alkyl group. In some embodiments, R^(L) isan optionally substituted branched alkyl group. In some embodiments,R^(L) is a substituted branched alkyl group. In some embodiments, R^(L)is an unsubstituted branched alkyl group.

In certain embodiments, at least one instance of R^(L) is anunsubstituted alkyl. Exemplary unsubstituted alkyl groups include, butare not limited to, —CH₃, —C₂H₅, —C₃H₇, —C₄H₉, —C₅H₁₁, —C₆H₁₃, —C₇H₁₅,—C₈H₁₇, —C₉H₁₉, —C₁₀H₂₁, —C₁₁H₂₃, —C₁₂H₂₅, —C₁₃H₂₇, —C₁₄H₂₉, —C₁₅H₃₁,—C₁₆H₃₃, —C₁₇H₃₅, —C₁₈H₃₇, —C₁₉H₃₉, —C₂₀H₄₁, —C₂₁H₄₃, —C₂₂H₄₅, —C₂₃H₄₇,—C₂₄H₄₉, and —C₂₅H₅₁.

In certain embodiments, at least one instance of R^(L) is a substitutedalkyl. For example, in certain embodiments, at least one instance ofR^(L) is an alkyl substituted with one or more fluorine substituents.Exemplary fluorinated alkyl groups include, but are not limited to:

In some embodiments, R^(L) is optionally substituted C₂₋₅₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₂₋₄₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₃₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₂₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₈ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₇ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₆ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₅ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₄ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₃ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₂ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₁ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₈ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₇ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₋₆ alkenyl.

In some embodiments, R^(L) is optionally substituted C₄₋₅₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₄₋₄₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₃₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₂₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₈ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₇ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₆ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₅ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₄ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₃ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₂ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₁ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₈ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₇ alkenyl. In someembodiments, R^(L) is optionally substituted C₄₋₆ alkenyl.

In some embodiments, R^(L) is optionally substituted C₆₋₅₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₆₋₄₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₃₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₂₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₈ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₇ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₆ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₅ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₄ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₃ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₂ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₁ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₈ alkenyl. In someembodiments, R^(L) is optionally substituted C₆₋₇ alkenyl.

In some embodiments, R^(L) is optionally substituted C₈₋₅₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₈₋₄₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₃₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₂₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₅₋₁₅ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₇ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₆ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₅ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₄ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₃ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₂ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₁ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₈₋₉ alkenyl.

In some embodiments, R^(L) is optionally substituted C₉₋₅₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₉₋₄₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₃₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₂₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₈ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₇ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₆ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₅ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₄ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₃ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₂ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₁ alkenyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₀ alkenyl.

In some embodiments, R^(L) is optionally substituted C₁₀₋₅₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₄₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₃₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₂₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₉ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₈ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₇ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₆ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₅ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₄ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₃ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₂ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₁ alkenyl.

In some embodiments, R^(L) is optionally substituted C₁₁₋₅₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₄₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₃₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₂₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₉ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₈ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₇ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₆ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₅ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₄ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₃ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₂ alkenyl.

In some embodiments, R^(L) is optionally substituted C₁₂₋₅₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₄₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₃₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₂₀ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₉ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₈ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₇ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₆ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₅ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₄ alkenyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₃ alkenyl.

In some embodiments, R^(L) is optionally substituted C₆ alkenyl. In someembodiments, R^(L) is optionally substituted C₇ alkenyl. In someembodiments, R^(L) is optionally substituted C₈ alkenyl. In someembodiments, R^(L) is optionally substituted C₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₀ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₁ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₂ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₃ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₄ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₅ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₆ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₇ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₈ alkenyl. In someembodiments, R^(L) is optionally substituted C₁₉ alkenyl. In someembodiments, R^(L) is optionally substituted C₂₀ alkenyl.

In some embodiments, for example, in any of the above embodiments, R^(L)is a substituted alkyl group. In some embodiments, R^(L) is anunsubstituted alkyl group. In some embodiments, R^(L) is an optionallysubstituted straight-chain alkenyl group. In some embodiments, R^(L) isa substituted straight-chain alkenyl group. In some embodiments, R^(L)is an unsubstituted straight-chain alkenyl group. In some embodiments,R^(L) is an optionally substituted branched alkenyl group. In someembodiments, R^(L) is a substituted branched alkenyl group. In someembodiments, R^(L) is an unsubstituted branched alkenyl group.

Exemplary unsubstituted alkenyl group include, but are not limited to:

Myristoleic —(CH₂)₇CH═CH(CH₂)₃CH₃, Palmitoliec —(CH₂)₇CH═CH(CH₂)₅CH₃,Sapienic —(CH₂)₄CH═CH(CH₂)₈CH₃, Oleic —(CH₂)₇CH═CH(CH₂)₇CH₃, Linoleic—(CH₂)₇CH═CHCH₂CH═CH(CH₂)₄CH₃, α-Linolenic—(CH₂)₇CH═CHCH₂CH═CHCH₂CH═CHCH₂CH₃, Arachinodonic—(CH₂)₃CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CH(CH₂)₄CH₃, Eicosapentaenoic—(CH₂)₃CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH₃, Erucic—(CH₂)₁₁CH═CH(CH₂)₇CH₃, and Docosahexaenoic—(CH₂)₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CH—CH₂CH₃.

In some embodiments, wherein R^(L) is defined as a C₆₋₅₀alkyl orC₆₋₅₀alkenyl groups, such groups are meant to encompass lipophilicgroups (also referred to as a “lipid tail”). Lipophilic groups comprisea group of molecules that include fats, waxes, oils, fatty acids, andthe like. Lipid tails present in these lipid groups can be saturated andunsaturated, depending on whether or not the lipid tail comprises doublebonds. The lipid tail can also comprise different lengths, oftencategorized as medium (i.e., with tails between 7-12 carbons, e.g.,C₇₋₁₂ alkyl or C₇₋₁₂ alkenyl), long (i.e., with tails greater than 12carbons and up to 22 carbons, e.g., C₁₃₋₂₂alkyl or C₁₃₋₂₂ alkenyl), orvery long (i.e., with tails greater than 22 carbons, e.g., C₂₃₋₃₀ alkylor C₂₃₋₃₀ alkenyl).

In some embodiments, R^(L) is optionally substituted C₂₋₅₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₂₋₄₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₃₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₂₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₈ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₇ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₆ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₅ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₄ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₃ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₂ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₁ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₁₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₈ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₇ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₋₆ alkynyl.

In some embodiments, R^(L) is optionally substituted C₄₋₅₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₄₋₄₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₃₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₂₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₈ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₇ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₆ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₅ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₄ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₃ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₂ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₁ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₁₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₈ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₇ alkynyl. In someembodiments, R^(L) is optionally substituted C₄₋₆ alkynyl.

In some embodiments, R^(L) is optionally substituted C₆₋₅₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₆₋₄₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₃₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₂₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₈ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₇ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₆ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₅ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₄ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₃ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₂ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₁ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₁₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₈ alkynyl. In someembodiments, R^(L) is optionally substituted C₆₋₇ alkynyl.

In some embodiments, R^(L) is optionally substituted C₈₋₅₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₈₋₄₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₃₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₂₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₅₋₁₅ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₇ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₆ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₅ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₄ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₃ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₂ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₁ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₁₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₈₋₉ alkynyl.

In some embodiments, R^(L) is optionally substituted C₉₋₅₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₉₋₄₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₃₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₂₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₈ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₇ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₆ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₅ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₄ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₃ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₂ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₁ alkynyl. In someembodiments, R^(L) is optionally substituted C₉₋₁₀ alkynyl.

In some embodiments, R^(L) is optionally substituted C₁₀₋₅₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₄₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₃₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₂₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₉ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₈ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₇ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₆ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₅ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₄ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₃ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₂ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₀₋₁₁ alkynyl.

In some embodiments, R^(L) is optionally substituted C₁₁₋₅₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₄₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₃₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₂₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₉ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₈ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₇ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₆ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₅ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₄ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₃ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₁₋₁₂ alkynyl.

In some embodiments, R^(L) is optionally substituted C₁₂₋₅₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₄₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₃₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₂₀ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₉ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₈ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₇ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₆ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₅ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₄ alkynyl. Insome embodiments, R^(L) is optionally substituted C₁₂₋₁₃ alkynyl.

In some embodiments, R^(L) is optionally substituted C₆ alkynyl. In someembodiments, R^(L) is optionally substituted C₇ alkynyl. In someembodiments, R^(L) is optionally substituted C₈ alkynyl. In someembodiments, R^(L) is optionally substituted C₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₀ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₁ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₂ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₃ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₄ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₅ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₆ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₇ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₈ alkynyl. In someembodiments, R^(L) is optionally substituted C₁₉ alkynyl. In someembodiments, R^(L) is optionally substituted C₂₀ alkynyl.

In some embodiments, for example, in any of the above embodiments, R^(L)is a substituted alkynyl group. In some embodiments, R^(L) is anunsubstituted alkynyl group. In some embodiments, R^(L) is an optionallysubstituted straight-chain alkyl group. In some embodiments, R^(L) is anoptionally substituted straight-chain alkynyl group. In someembodiments, R^(L) is a substituted straight-chain alkynyl group. Insome embodiments, R^(L) is an unsubstituted straight-chain alkynylgroup. In some embodiments, R^(L) is an optionally substituted branchedalkynyl group. In some embodiments, R^(L) is a substituted branchedalkynyl group. In some embodiments, R^(L) is an unsubstituted branchedalkynyl group.

In some embodiments, R^(L) is optionally substituted heteroC₁₋₅₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₅₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₄₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₃₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₂₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₉alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₈alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₇alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₆alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₄alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₃alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₂alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₁alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₉alkyl. Insome embodiments, R^(L) is optionally substituted heteroC₂₋₅alkyl. Insome embodiments, R^(L) is optionally substituted heteroC₂₋₇alkyl. Insome embodiments, R^(L) is optionally substituted heteroC₂₋₆alkyl.

In some embodiments, R^(L) is optionally substituted heteroC₄₋₅₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₄₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₃₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₂₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₉alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₈alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₇alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₆alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₄alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₃alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₂alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₁alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₉alkyl. Insome embodiments, R^(L) is optionally substituted heteroC₄₋₅alkyl. Insome embodiments, R^(L) is optionally substituted heteroC₄₋₇alkyl. Insome embodiments, R^(L) is optionally substituted heteroC₄₋₆alkyl.

In some embodiments, R^(L) is optionally substituted heteroC₆₋₅₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₄₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₃₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₂₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₉alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₈alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₇alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₆alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₄alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₃alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₂alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₁alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₉alkyl. Insome embodiments, R^(L) is optionally substituted heteroC₆₋₅alkyl. Insome embodiments, R^(L) is optionally substituted heteroC₆₋₇alkyl.

In some embodiments, R^(L) is optionally substituted heteroC₈₋₅₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₄₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₃₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₂₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₉alkyl.In some embodiments, R^(L) is optionally substituted heteroC₅₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₇alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₆alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₄alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₃alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₂alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₁alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₉alkyl.

In some embodiments, R^(L) is optionally substituted heteroC₉₋₅₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₄₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₃₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₂₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₉alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₈alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₇alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₆alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₄alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₃alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₂alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₁alkyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₀alkyl.

In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₅₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₄₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₃₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₂₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₉alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₇alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₆alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₄alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₃alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₂alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₁alkyl.

In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₅₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₄₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₃₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₂₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₁₉alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₁₈alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₁₇alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₁₆alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₁₄alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₁₃alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₁₋₁₂alkyl.

In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₅₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₄₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₃₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₂₀alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₁₉alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₁₈alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₁₇alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₁₆alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₁₅alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₁₄alkyl.In some embodiments, R^(L) is optionally substituted heteroC₁₂₋₁₃alkyl.

In some embodiments, R^(L) is optionally substituted heteroC₆alkyl. Insome embodiments, R^(L) is optionally substituted heteroC₇alkyl. In someembodiments, R^(L) is optionally substituted heteroC₈alkyl. In someembodiments, R^(L) is optionally substituted heteroC₉alkyl. In someembodiments, R^(L) is optionally substituted heteroC₁₀alkyl. In someembodiments, R^(L) is optionally substituted heteroC₁₁alkyl. In someembodiments, R^(L) is optionally substituted heteroC₂alkyl. In someembodiments, R^(L) is optionally substituted heteroC₁₃alkyl. In someembodiments, R^(L) is optionally substituted heteroC₁₄alkyl. In someembodiments, R^(L) is optionally substituted heteroC₁₅alkyl. In someembodiments, R^(L) is optionally substituted heteroC₁₆alkyl. In someembodiments, R^(L) is optionally substituted heteroC₁₇alkyl. In someembodiments, R^(L) is optionally substituted heteroC₁₈alkyl. In someembodiments, R^(L) is optionally substituted heteroC₁₉alkyl. In someembodiments, R^(L) is optionally substituted heteroC₂₀alkyl.

In some embodiments, for example, in any of the above embodiments, R^(L)is a substituted heteroalkyl group. In some embodiments, R^(L) is anunsubstituted heteroalkyl group. In some embodiments, R^(L) is anoptionally substituted straight-chain heteroalkyl group. In someembodiments, R^(L) is a substituted straight-chain heteroalkyl group. Insome embodiments, R^(L) is an unsubstituted straight-chain heteroalkylgroup. In some embodiments, R^(L) is an optionally substituted branchedheteroalkyl group. In some embodiments, R^(L) is a substituted branchedheteroalkyl group. In some embodiments, R^(L) is an unsubstitutedbranched heteroalkyl group.

Exemplary unsubstituted heteroalkyl groups include, but are not limitedto:

In some embodiments, R^(L) is optionally substituted heteroC₂₋₅₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₄₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₃₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₂₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₉alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₈alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₇alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₆alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₅alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₄alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₃alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₂alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₁alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₉alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₈alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₇alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₆alkenyl.

In some embodiments, R^(L) is optionally substituted heteroC₄₋₅₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₄₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₃₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₂₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₉alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₈alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₇alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₆alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₅alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₄alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₃alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₂alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₁alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₉alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₅alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₇alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₆alkenyl.

In some embodiments, R^(L) is optionally substituted heteroC₆₋₅₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₄₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₃₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₂₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₉alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₅alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₇alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₆alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₅alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₄alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₃alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₂alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₁alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₉alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₅alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₇alkenyl.

In some embodiments, R^(L) is optionally substituted heteroC₈₋₅₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₄₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₃₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₂₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₉alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₈alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₇alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₆alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₅alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₄alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₃alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₂alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₁alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₉alkenyl.

In some embodiments, R^(L) is optionally substituted heteroC₉₋₅₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₄₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₃₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₂₀alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₉alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₈alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₇alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₆alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₅alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₄alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₃alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₂alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₁alkenyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₀alkenyl.

In some embodiments, R^(L) is optionally substitutedheteroC₁₀₋₅₀alkenyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₀₋₄₀alkenyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₀₋₃₀alkenyl. In some embodiments, R^(L)is optionally substituted heteroC₁₀₋₂₀alkenyl. In some embodiments,R^(L) is optionally substituted heteroC₁₀₋₁₉alkenyl. In someembodiments, R^(L) is optionally substituted heteroC₁₀₋₁₅alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₇alkenyl.In some embodiments, R^(L) is optionally substitutedheteroC₁₀₋₁₆alkenyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₀₋₁₅alkenyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₀₋₁₄alkenyl. In some embodiments, R^(L)is optionally substituted heteroC₁₀₋₁₃alkenyl. In some embodiments,R^(L) is optionally substituted heteroC₁₀₋₁₂alkenyl. In someembodiments, R^(L) is optionally substituted heteroC₁₀₋₁₁alkenyl.

In some embodiments, R^(L) is optionally substitutedheteroC₁₁₋₅₀alkenyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₁₋₄₀alkenyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₁₋₃₀alkenyl. In some embodiments, R^(L)is optionally substituted heteroC₁₁₋₂₀alkenyl. In some embodiments,R^(L) is optionally substituted heteroC₁₁₋₁₉alkenyl. In someembodiments, R^(L) is optionally substituted heteroC₁₁₋₁₈alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₁₋₁₇alkenyl.In some embodiments, R^(L) is optionally substitutedheteroC₁₁₋₁₆alkenyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₋₁₅alkenyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₁₋₁₄alkenyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₁₋₁₃alkenyl. In some embodiments, R^(L)is optionally substituted heteroC₁₁₋₁₂alkenyl.

In some embodiments, R^(L) is optionally substitutedheteroC₁₂₋₅₀alkenyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₂₋₄₀alkenyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₂₋₃₀alkenyl. In some embodiments, R^(L)is optionally substituted heteroC₁₂₋₂₀alkenyl. In some embodiments,R^(L) is optionally substituted heteroC₁₂₋₁₉alkenyl. In someembodiments, R^(L) is optionally substituted heteroC₁₂₋₁₈alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₂₋₁₇alkenyl.In some embodiments, R^(L) is optionally substitutedheteroC₁₂₋₁₆alkenyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₂₋₁₅alkenyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₂₋₁₄alkenyl. In some embodiments, R^(L)is optionally substituted heteroC₁₂₋₁₃alkenyl.

In some embodiments, R^(L) is optionally substituted heteroC₆alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₇alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₈alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₉alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₀alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₁alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₂alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₃alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₄alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₅alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₆alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₇alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₈alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₉alkenyl. Insome embodiments, R^(L) is optionally substituted heteroC₂₀alkenyl.

In some embodiments, for example, in any of the above embodiments, R^(L)is a substituted heteroalkenyl group. In some embodiments, R^(L) is anunsubstituted heteroalkenyl group. In some embodiments, R^(L) is anoptionally substituted straight-chain heteroalkenyl group. In someembodiments, R^(L) is a substituted straight-chain heteroalkenyl group.In some embodiments, R^(L) is an unsubstituted straight-chainheteroalkenyl group. In some embodiments, R^(L) is an optionallysubstituted branched heteroalkenyl group. In some embodiments, R^(L) isa substituted branched heteroalkenyl group. In some embodiments, R^(L)is an unsubstituted branched heteroalkenyl group.

In some embodiments, R^(L) is optionally substituted heteroC₂₋₅₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₄₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₃₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₂₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₉alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₈alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₇alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₆alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₅alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₄alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₃alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₂alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₁alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₁₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₉alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₈alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₇alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₂₋₆alkynyl.

In some embodiments, R^(L) is optionally substituted heteroC₄₋₅₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₄₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₃₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₂₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₉alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₅alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₇alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₆alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₅alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₄alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₃alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₂alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₁alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₁₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₉alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₅alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₇alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₄₋₆alkynyl.

In some embodiments, R^(L) is optionally substituted heteroC₆₋₅₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₄₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₃₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₂₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₉alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₅alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₇alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₆alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₅alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₄alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₃alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₂alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₁alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₁₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₉alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₅alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₆₋₇alkynyl.

In some embodiments, R^(L) is optionally substituted heteroC₈₋₅₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₄₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₃₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₂₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₉alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₈alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₇alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₆alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₅alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₄alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₃alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₂alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₁alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₁₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₈₋₉alkynyl.

In some embodiments, R^(L) is optionally substituted heteroC₉₋₅₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₄₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₃₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₂₀alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₉alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₈alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₇alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₆alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₅alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₄alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₃alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₂alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₁alkynyl.In some embodiments, R^(L) is optionally substituted heteroC₉₋₁₀alkynyl.

In some embodiments, R^(L) is optionally substitutedheteroC₁₀₋₅₀alkynyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₀₋₄₀alkynyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₀₋₃₀alkynyl. In some embodiments, R^(L)is optionally substituted heteroC₁₀₋₂₀alkynyl. In some embodiments,R^(L) is optionally substituted heteroC₁₀₋₁₉alkynyl. In someembodiments, R^(L) is optionally substituted heteroC₁₀₋₁₅alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₀₋₁₇alkynyl.In some embodiments, R^(L) is optionally substitutedheteroC₁₀₋₁₆alkynyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₀₋₁₅alkynyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₀₋₁₄alkynyl. In some embodiments, R^(L)is optionally substituted heteroC₁₀₋₁₃alkynyl. In some embodiments,R^(L) is optionally substituted heteroC₁₀₋₁₂alkynyl. In someembodiments, R^(L) is optionally substituted heteroC₁₀₋₁₁alkynyl.

In some embodiments, R^(L) is optionally substitutedheteroC₁₁₋₅₀alkynyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₁₋₄₀alkynyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₁₋₃₀alkynyl. In some embodiments, R^(L)is optionally substituted heteroC₁₁₋₂₀alkynyl. In some embodiments,R^(L) is optionally substituted heteroC₁₁₋₁₉alkynyl. In someembodiments, R^(L) is optionally substituted heteroC₁₁₋₁₈alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₁₋₁₇alkynyl.In some embodiments, R^(L) is optionally substitutedheteroC₁₁₋₁₆alkynyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₁₋₁₅alkynyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₁₋₁₄alkynyl. In some embodiments, R^(L)is optionally substituted heteroC₁₁₋₁₃alkynyl. In some embodiments,R^(L) is optionally substituted heteroC₁₁₋₁₂alkynyl.

In some embodiments, R^(L) is optionally substitutedheteroC₁₂₋₅₀alkynyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₂₋₄₀alkynyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₂₋₃₀alkynyl. In some embodiments, R^(L)is optionally substituted heteroC₁₂₋₂₀alkynyl. In some embodiments,R^(L) is optionally substituted heteroC₁₂₋₁₉alkynyl. In someembodiments, R^(L) is optionally substituted heteroC₁₂₋₁₈alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₂₋₁₇alkynyl.In some embodiments, R^(L) is optionally substitutedheteroC₁₂₋₁₆alkynyl. In some embodiments, R^(L) is optionallysubstituted heteroC₁₂₋₁₅alkynyl. In some embodiments, R^(L) isoptionally substituted heteroC₁₂₋₁₄alkynyl. In some embodiments, R^(L)is optionally substituted heteroC₁₂₋₁₃alkynyl.

In some embodiments, R^(L) is optionally substituted heteroC₆alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₇alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₈alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₉alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₀alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₁alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₂alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₃alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₄alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₅alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₆alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₇alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₈alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₁₉alkynyl. Insome embodiments, R^(L) is optionally substituted heteroC₂₀alkynyl.

In some embodiments, for example, in any of the above embodiments, R^(L)is a substituted heteroalkynyl group. In some embodiments, R^(L) is anunsubstituted heteroalkynyl group. In some embodiments, R^(L) is anoptionally substituted straight-chain heteroalkynyl group. In someembodiments, R^(L) is a substituted straight-chain heteroalkynyl group.In some embodiments, R^(L) is an unsubstituted straight-chainheteroalkynyl group. In some embodiments, R^(L) is an optionallysubstituted branched heteroalkynyl group. In some embodiments, R^(L) isa substituted branched heteroalkynyl group. In some embodiments, R^(L)is an unsubstituted branched heteroalkynyl group.

In some embodiments, R^(L) is a polymer. As used herein, a “polymer”, insome embodiments, refers to a compound comprised of at least 3 (e.g., atleast 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, etc.) repeatingcovalently bound structural units. The polymer is in certain embodimentsbiocompatible (i.e., non-toxic). Exemplary polymers include, but are notlimited to, cellulose polymers (e.g., hydroxyethylcellulose,ethylcellulose, carboxymethylcellulose, methylcellulose,hydroxypropylmethylcellulose (HPMC)), dextran polymers, polymaleic acidpolymers, poly(acrylic acid) polymers, poly(vinylalcohol) polymers,polyvinylpyrrolidone (PVP) polymers, and polyethyleneglycol (PEG)polymers, and combinations thereof.

In some embodiments, R^(L) is a lipophilic, hydrophobic and/or non-polargroup. In some embodiments, R^(L) is a lipophilic group. In someembodiments, R^(L) is a hydrophobic group. In some embodiments, R^(L) isa non-polar group.

In some embodiments, when an R^(L) group is depicted as bisecting acarbon-carbon bond, e.g., of the formula (i), it is understood thatR^(L) may be bonded to either carbon.

In some embodiments, at least one instance of R^(Q), R², R⁶, or R⁷ is agroup of the formula (i), (ii), or (iii). In some embodiments, at leastone instance of R⁶ or R⁷ of R¹ is a group of formula (i), (ii) or (iii).In some embodiments, at least one instance of R⁶ or R⁷ of R¹ is a groupof formula (i). In some embodiments, at least one instance of R⁶ or R⁷of R¹ is a group of formula (i-a). In some embodiments, at least oneinstance of R⁶ or R⁷ of R¹ is a group of formula (i-a1). In someembodiments, at least one instance of R⁶ or R⁷ of R¹ is a group offormula (i-b). In some embodiments, at least one instance of R⁶ or R⁷ ofR¹ is a group of formula (ii). In some embodiments, at least oneinstance of R⁶ or R⁷ of R¹ is a group of formula (iii).

In some embodiments, the compound (i.e., cationic lipid) of formula I isa compound according to formula II:

or a pharmaceutically acceptable salt thereof,

wherein:

-   -   each m independently is 1 to 19;    -   each n is independently is 1 to 6;    -   each X independently is O or S;    -   each Y independently is O or S;    -   each R_(A) is independently hydrogen, optionally substituted        C1-50 alkyl, optionally substituted C2-50 alkenyl, optionally        substituted C2-50 alkynyl, optionally substituted C3-10        carbocyclyl, optionally substituted 3-14 membered heterocyclyl,        optionally substituted C6-14 aryl, optionally substituted 5-14        membered heteroaryl or halogen, wherein each alkyl, alkenyl,        alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is        independently substituted with 0, 1, 2, 3, 4, or 5 Rdd groups,        and    -   each R_(B) is independently hydrogen, optionally substituted        C1-50 alkyl, optionally substituted C2-50 alkenyl, optionally        substituted C2-50 alkynyl, optionally substituted C3-10        carbocyclyl, optionally substituted 3-14 membered heterocyclyl,        optionally substituted C6-14 aryl, optionally substituted 5-14        membered heteroaryl or halogen, wherein each alkyl, alkenyl,        alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is        independently substituted with 0, 1, 2, 3, 4, or 5 Rdd groups.

In some embodiments, each n independently is 2 to 6. In someembodiments, each n independently is 3 to 5. In some embodiments, each nindependently is 3 or 4. In some embodiments, each n is the same. Insome embodiments, each n is 2. In some embodiments, each n is 3. In someembodiments, each n is 4. In some embodiments, each n is 5. In someembodiments, each n is 6.

In some embodiments, each m independently is 1 to 17. In someembodiments, each m independently is 3 to 15. In some embodiments, eachm independently is 5 to 13. In some embodiments, each m independently is7 to 11. In some embodiments, each m independently is 8 to 10. In someembodiments, each m is the same. In some embodiments, each m is 7. Insome embodiments, each m is 8. In some embodiments, each m is 9. In someembodiments, each m is 10. In some embodiments, each m is 11.

In some embodiments, each X is the same. In some embodiments, each X isO. In some embodiments, each X is S. In some embodiments, one X is O andone X is S.

In some embodiments, each Y is the same. In some embodiments, each Y isO. In some embodiments, each Y is S. In some embodiments, one Y is O andone Y is S.

In some embodiments, each X is the same and each Y is the same. In someembodiments, each X is O and each Y is O. In some embodiments, each X isS and each Y is S.

In some embodiments, R_(A) is hydrogen. In some embodiments, R_(A) isoptionally substituted C2-50 alkenyl. In some embodiments, R_(A) isoptionally substituted C2-50 alkynyl. In some embodiments, R_(A) isoptionally substituted C3-10 carbocyclyl. In some embodiments, R_(A) isoptionally substituted 3-14 membered heterocyclyl. In some embodiments,R_(A) is optionally substituted C6-14 aryl. In some embodiments, R_(A)is optionally substituted 5-14 membered heteroaryl. In some embodiments,R_(A) is halogen.

In certain embodiments, R_(A) is optionally substituted alkyl; e.g.,optionally substituted C₁₋₆alkyl, optionally substituted C₂₋₆alkyl,optionally substituted C₃₋₆alkyl, optionally substituted C₄₋₆alkyl,optionally substituted C₄₋₅alkyl, or optionally substituted C₃₋₄alkyl.In certain embodiments, at least one instance of R_(A) is optionallysubstituted alkyl; e.g., optionally substituted C₁₋₆alkyl, optionallysubstituted C₂₋₆alkyl, optionally substituted C₃₋₆alkyl, optionallysubstituted C₄₋₆alkyl, optionally substituted C₄₋₅alkyl, or optionallysubstituted C₃₋₄alkyl. In certain embodiments, R_(A) is methyl.

In certain embodiments, R_(A) is optionally substituted alkenyl, e.g.,optionally substituted C₂₋₆alkenyl, optionally substituted C₃₋₆alkenyl,optionally substituted C₄₋₆alkenyl, optionally substituted C₄₋₅alkenyl,or optionally substituted C₃₋₄alkenyl. In certain embodiments, at leastone instance of R_(A) is optionally substituted alkenyl, e.g.,optionally substituted C₂₋₆alkenyl, optionally substituted C₃₋₆alkenyl,optionally substituted C₄₋₆alkenyl, optionally substituted C₄₋₅alkenyl,or optionally substituted C₃₋₄alkenyl.

In certain embodiments, R_(A) is optionally substituted alkynyl, e.g.,optionally substituted C₂₋₆alkynyl, optionally substituted C₃₋₆alkynyl,optionally substituted C₄₋₆alkynyl, optionally substituted C₄₋₅alkynyl,or optionally substituted C₃₋₄alkynyl. In certain embodiments, at leastone instance of R_(A) is optionally substituted alkynyl, e.g.,optionally substituted C₂₋₆alkynyl, optionally substituted C₃₋₆alkynyl,optionally substituted C₄₋₆alkynyl, optionally substituted C₄₋₅alkynyl,or optionally substituted C₃₋₄alkynyl.

In certain embodiments, R_(A) is optionally substituted carbocyclyl,e.g., optionally substituted C₃₋₁₀ carbocyclyl, optionally substitutedC₅₋₈ carbocyclyl, optionally substituted C₅₋₆ carbocyclyl, optionallysubstituted C₅ carbocyclyl, or optionally substituted C₆ carbocyclyl. Incertain embodiments, at least one instance of R_(A) is optionallysubstituted carbocyclyl, e.g., optionally substituted C₃₋₁₀ carbocyclyl,optionally substituted C₅₋₈ carbocyclyl, optionally substituted C₅₋₆carbocyclyl, optionally substituted C₅ carbocyclyl, or optionallysubstituted C₆ carbocyclyl.

In some embodiments, R_(A) is optionally substituted heterocyclyl, e.g.,optionally substituted 3-14 membered heterocyclyl, optionallysubstituted 3-10 membered heterocyclyl, optionally substituted 5-8membered heterocyclyl, optionally substituted 5-6 membered heterocyclyl,optionally substituted 5-membered heterocyclyl, or optionallysubstituted 6-membered heterocyclyl. In certain embodiments, at leastone instance of R_(A) is optionally substituted heterocyclyl, e.g.,optionally substituted 3-14 membered heterocyclyl, optionallysubstituted 3-10 membered heterocyclyl, optionally substituted 5-8membered heterocyclyl, optionally substituted 5-6 membered heterocyclyl,optionally substituted 5-membered heterocyclyl, or optionallysubstituted 6-membered heterocyclyl.

In some embodiments, R_(A) is optionally substituted aryl. In someembodiments, R_(A) is optionally substituted phenyl. In someembodiments, R_(A) is phenyl. In some embodiments, R_(A) is substitutedphenyl. In certain embodiments, at least one instance of R_(A) isoptionally substituted aryl, e.g., optionally substituted phenyl.

In some embodiments, R_(A) is optionally substituted heteroaryl, e.g.,optionally substituted 5-14 membered heteroaryl, optionally substituted5-10 membered heteroaryl, optionally substituted 5-6 memberedheteroaryl, optionally substituted 5 membered heteroaryl, or optionallysubstituted 6 membered heteroaryl. In certain embodiments, at least oneinstance of R_(A) is optionally substituted heteroaryl, e.g., optionallysubstituted 5-14 membered heteroaryl, optionally substituted 5-10membered heteroaryl, optionally substituted 5-6 membered heteroaryl,optionally substituted 5 membered heteroaryl, or optionally substituted6 membered heteroaryl.

In some embodiments, R_(A) is halogen. In some embodiments, R_(A) is —F.In some embodiments, R_(A) is —Cl. In some embodiments, R_(A) is —Br. Insome embodiments, R_(A) is —I.

In some embodiments, R_(B) is hydrogen. In some embodiments, R_(B) isoptionally substituted C1-50 alkyl. In some embodiments, R_(B) isoptionally substituted C2-50 alkenyl. In some embodiments, R_(B) isoptionally substituted C2-50 alkynyl. In some embodiments, R_(B) isoptionally substituted C3-10 carbocyclyl. In some embodiments, R_(B) isoptionally substituted 3-14 membered heterocyclyl. In some embodiments,R_(B) is optionally substituted C6-14 aryl. In some embodiments, R_(B)is optionally substituted 5-14 membered heteroaryl. In some embodiments,R_(B) is halogen.

In certain embodiments, R_(B) is optionally substituted alkyl; e.g.,optionally substituted C₁₋₆alkyl, optionally substituted C₂₋₆alkyl,optionally substituted C₃₋₆alkyl, optionally substituted C₄₋₆alkyl,optionally substituted C₄₋₅alkyl, or optionally substituted C₃₋₄alkyl.In certain embodiments, at least one instance of R_(B) is optionallysubstituted alkyl; e.g., optionally substituted C₁₋₆alkyl, optionallysubstituted C₂₋₆alkyl, optionally substituted C₃₋₆alkyl, optionallysubstituted C₄₋₆alkyl, optionally substituted C₄₋₅alkyl, or optionallysubstituted C₃₋₄alkyl. In certain embodiments, R_(B) is methyl.

In certain embodiments, R_(B) is optionally substituted alkenyl, e.g.,optionally substituted C₂₋₆alkenyl, optionally substituted C₃₋₆alkenyl,optionally substituted C₄₋₆alkenyl, optionally substituted C₄₋₅alkenyl,or optionally substituted C₃₋₄alkenyl. In certain embodiments, at leastone instance of R_(B) is optionally substituted alkenyl, e.g.,optionally substituted C₂₋₆alkenyl, optionally substituted C₃₋₆alkenyl,optionally substituted C₄₋₆alkenyl, optionally substituted C₄₋₅alkenyl,or optionally substituted C₃₋₄alkenyl.

In certain embodiments, R_(B) is optionally substituted alkynyl, e.g.,optionally substituted C₂₋₆alkynyl, optionally substituted C₃₋₆alkynyl,optionally substituted C₄₋₆alkynyl, optionally substituted C₄₋₅alkynyl,or optionally substituted C₃₋₄alkynyl. In certain embodiments, at leastone instance of R_(B) is optionally substituted alkynyl, e.g.,optionally substituted C₂₋₆alkynyl, optionally substituted C₃₋₆alkynyl,optionally substituted C₄₋₆alkynyl, optionally substituted C₄₋₅alkynyl,or optionally substituted C₃₋₄alkynyl.

In certain embodiments, R_(B) is optionally substituted carbocyclyl,e.g., optionally substituted C₃₋₁₀ carbocyclyl, optionally substitutedC₅₋₈ carbocyclyl, optionally substituted C₅₋₆ carbocyclyl, optionallysubstituted C₅ carbocyclyl, or optionally substituted C₆ carbocyclyl. Incertain embodiments, at least one instance of R_(B) is optionallysubstituted carbocyclyl, e.g., optionally substituted C₃₋₁₀ carbocyclyl,optionally substituted C₅₋₈ carbocyclyl, optionally substituted C₅₋₆carbocyclyl, optionally substituted C₅ carbocyclyl, or optionallysubstituted C₆ carbocyclyl.

In some embodiments, R_(B) is optionally substituted heterocyclyl, e.g.,optionally substituted 3-14 membered heterocyclyl, optionallysubstituted 3-10 membered heterocyclyl, optionally substituted 5-8membered heterocyclyl, optionally substituted 5-6 membered heterocyclyl,optionally substituted 5-membered heterocyclyl, or optionallysubstituted 6-membered heterocyclyl. In certain embodiments, at leastone instance of R_(B) is optionally substituted heterocyclyl, e.g.,optionally substituted 3-14 membered heterocyclyl, optionallysubstituted 3-10 membered heterocyclyl, optionally substituted 5-8membered heterocyclyl, optionally substituted 5-6 membered heterocyclyl,optionally substituted 5-membered heterocyclyl, or optionallysubstituted 6-membered heterocyclyl.

In some embodiments, R_(B) is optionally substituted aryl. In someembodiments, R_(B) is optionally substituted phenyl. In someembodiments, R_(B) is phenyl. In some embodiments, R_(B) is substitutedphenyl. In certain embodiments, at least one instance of R_(B) isoptionally substituted aryl, e.g., optionally substituted phenyl.

In some embodiments, R_(B) is optionally substituted heteroaryl, e.g.,optionally substituted 5-14 membered heteroaryl, optionally substituted5-10 membered heteroaryl, optionally substituted 5-6 memberedheteroaryl, optionally substituted 5 membered heteroaryl, or optionallysubstituted 6 membered heteroaryl. In certain embodiments, at least oneinstance of R_(B) is optionally substituted heteroaryl, e.g., optionallysubstituted 5-14 membered heteroaryl, optionally substituted 5-10membered heteroaryl, optionally substituted 5-6 membered heteroaryl,optionally substituted 5 membered heteroaryl, or optionally substituted6 membered heteroaryl.

In some embodiments, R_(B) is halogen. In some embodiments, R_(B) is —F.In some embodiments, R_(B) is —Cl. In some embodiments, R_(B) is —Br. Insome embodiments, R_(B) is —I.

In some embodiments, at least one R_(A) is optionally substituted C1-50alkyl. In some embodiments, at least one R_(A) and one R_(B) areoptionally substituted C1-50 alkyl. In some embodiments, at least oneR_(A) and one R_(B) are optionally substituted C1-50 alkyl, where theR_(A) and R_(B) are attached to the same carbon. In some embodiments, atleast one R_(A) is methyl. In some embodiments, at least one R_(A) andone R_(B) are methyl. In some embodiments, at least one R_(A) and oneR_(B) are methyl, where the R_(A) and R_(B) are attached to the samecarbon.

In some embodiments, a compound of formula II is a compound of formulaII-a:

or a pharmaceutically acceptable salt thereof,wherein m and n are as defined above and described herein.

In some embodiments, a compound of formula II is a compound of formulaII-a wherein each n independently is 2 to 6 and each m independently is3 to 15. In some embodiments, a compound of formula II is a compound offormula II-a wherein each n independently is 3 to 5 and each mindependently is 5 to 13. In some embodiments, a compound of formula IIis a compound of formula II-a wherein each n independently is 3 or 4 andeach m independently is 7 to 11. In some embodiments, a compound offormula II is a compound of formula II-a wherein each n is the same andis 3 or 4, and each m is the same and is 7 to 11.

In some embodiments, a compound of formula II is a compound of formulaIII:

or a pharmaceutically acceptable salt thereof.

In some embodiments, a compound of formula II is a compound of formulaIV:

or a pharmaceutically acceptable salt thereof.

In some embodiments, a compound of formula II is a compound of formulaV:

or a pharmaceutically acceptable salt thereof.Liposomes for the Delivery of Agents, Such as mRNA

Among other things, the present invention provides compositioncomprising a biodegradable compound described herein for delivery oftherapeutic agents. In some embodiments, a composition provided is alipid based nanoparticle, such as a liposome. As used herein, the term“liposome” refers to any lamellar, multilamellar, or solid lipidnanoparticle vesicle. Typically, a liposome as used herein can be formedby mixing one or more lipids or by mixing one or more lipids andpolymer(s). Thus, the term “liposome” as used herein encompasses bothlipid and polymer based nanoparticles. In particular, a liposomeaccording to the present invention incorporates a biodegradable compounddescribed herein as a cationic lipid. As a non-limiting example, aliposome according to the present invention is a compound of formula IIIi.e.,3,6-bis(4-(bis(2-hydroxydodecyl)amino)butyl)-1,4-dioxane-2,5-dione. Asuitable liposome may also contain second or additional cationic lipids,helper lipids (e.g., non-cationic lipids and/or cholesterol-basedlipids), PEG-modified lipids, and/or polymers.

In some embodiments, cationic lipid(s) (e.g., the compound of formulaIII) constitute(s) about 30-50% (e.g., about 30-45%, about 30-40%, about35-50%, about 35-45%, or about 35-40%) of the liposome by molar ratio.In some embodiments, the cationic lipid (e.g., the compound of formulaIII) constitutes about 30%, about 35%, about 40%, about 45%, or about50% of the liposome by molar ratio. In some embodiments, the liposomecomprises a second lipid or additional cationic lipids.

Second or Additional Cationic Lipids

In some embodiments, liposomes may comprise a second or additionalcationic lipid. As used herein, the phrase “cationic lipid” refers toany of a number of lipid species that have a net positive charge at aselected pH, such as physiological pH. Several cationic lipids have beendescribed in the literature, many of which are commercially available.Particularly suitable cationic lipids for use in the compositions andmethods of the invention include those described in international patentpublications WO 2010/053572 (and particularly, C12-200 described atparagraph [00225]), WO 2012/170930 and WO 2013063468 each of which isincorporated herein by reference in its entirety. In certainembodiments, the compositions and methods of the invention employ alipid nanoparticles comprising an ionizable (titratable) cationic lipiddescribed in International Patent Application No. PCT/US2013/034602,filed Mar. 29, 2013, Publ. No. WO 2013/149140 (incorporated herein byreference), such as, e.g, (15Z, 18Z)—N,N-dimethyl-6-(9Z,12Z)-octadeca-9, 12-dien-1-yl)tetracosa-15,18-dien-1-amine (HGT5000),(15Z, 18Z)—N,N-dimethyl-6-((9Z, 12Z)-octadeca-9,12-dien-1-yl)tetracosa-4,15,18-trien-1-amine (HGT5001), and(15Z,18Z)—N,N-dimethyl-6-((9Z, 12Z)-octadeca-9,12-dien-1-yl)tetracosa-5, 15, 18-trien-1-amine (HGT5002).

In some embodiments, the second or additional cationic lipid is cKK-E12(3,6-bis(4-(bis(2-hydroxydodecyl)amino)butyl)piperazine-2,5-dione) orderivatives thereof, as described in international patent publicationsWO 2013/063468 incorporated herein by reference in its entirety.

In some embodiments, the second or additional cationic lipidN-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethylammonium chloride or “DOTMA”is used. (Feigner et al. (Proc. Nat'l Acad. Sci. 84, 7413 (1987); U.S.Pat. No. 4,897,355). DOTMA can be formulated alone or can be combinedwith the neutral lipid, dioleoylphosphatidyl-ethanolamine or “DOPE” orother cationic or non-cationic lipids into a liposomal transfer vehicleor a lipid nanoparticle, and such liposomes can be used to enhance thedelivery of nucleic acids into target cells. Other suitable cationiclipids include, for example, 5-carboxyspermylglycinedioctadecylamide or“DOGS,”2,3-dioleyloxy-N-[2(spermine-carboxamido)ethyl]-N,N-dimethyl-1-propanaminiumor “DOSPA” (Behr et al. Proc. Nat.'l Acad. Sci. 86, 6982 (1989); U.S.Pat. Nos. 5,171,678; 5,334,761), 1,2-Dioleoyl-3-Dimethylammonium-Propaneor “DODAP”, 1,2-Dioleoyl-3-Trimethylammonium-Propane or “DOTAP”.Additional exemplary cationic lipids also include1,2-distearyloxy-N,N-dimethyl-3-aminopropane or “DSDMA”,1,2-dioleyloxy-N,N-dimethyl-3-aminopropane or “DODMA”,1,2-dilinoleyloxy-N,N-dimethyl-3-aminopropane or “DLinDMA”,1,2-dilinolenyloxy-N,N-dimethyl-3-aminopropane or “DLenDMA”,N-dioleyl-N,N-dimethylammonium chloride or “DODAC”,N,N-distearyl-N,N-dimethylarnrnonium bromide or “DDAB”,N-(1,2-dimyristyloxyprop-3-yl)-N,N-dimethyl-N-hydroxyethyl ammoniumbromide or “DMRIE”,3-dimethylamino-2-(cholest-5-en-3-beta-oxybutan-4-oxy)-1-(cis,cis-9,12-octadecadienoxy)propaneor “CLinDMA”, 2-[5′-(cholest-5-en-3-beta-oxy)-3′-oxapentoxy)-3-dimethy1-1-(cis,cis-9′, 1-2′-octadecadienoxy)propane or “CpLinDMA”,N,N-dimethyl-3,4-dioleyloxybenzylamine or “DMOBA”,1,2-N,N′-dioleylcarbamyl-3-dimethylaminopropane or “DOcarbDAP”,2,3-Dilinoleoyloxy-N,N-dimethylpropylamine or “DLinDAP”,1,2-N,N′-Dilinoleylcarbamyl-3-dimethylaminopropane or “DLincarbDAP”,1,2-Dilinoleoylcarbamyl-3-dimethylaminopropane or “DLinCDAP”,2,2-dilinoleyl-4-dimethylaminomethyl-[1,3]-dioxolane or “DLin-DMA”,2,2-dilinoleyl-4-dimethylaminoethyl-[1,3]-dioxolane or“DLin-K-XTC2-DMA”, and2-(2,2-di((9Z,12Z)-octadeca-9,12-dien-1-yl)-1,3-dioxolan-4-yl)-N,N-dimethylethanamine(DLin-KC2-DMA)) (See, WO 2010/042877; Semple et al., Nature Biotech. 28:172-176 (2010)), or mixtures thereof. (Heyes, J., et al., J ControlledRelease 107: 276-287 (2005); Morrissey, D V., et al., Nat. Biotechnol.23(8): 1003-1007 (2005); PCT Publication WO2005/121348A1). In someembodiments, one or more of the cationic lipids comprise at least one ofan imidazole, dialkylamino, or guanidinium moiety.

In some embodiments, the second or additional cationic lipid may bechosen from XTC (2,2-Dilinoleyl 1-4-dimethylaminoethyl-[1,3]-dioxolane),MC3 (((6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl4-(dimethylamino)butanoate), ALNY-100((3aR,5s,6aS)—N,N-dimethyl-2,2-di((9Z,12Z)-octadeca-9,12-dienyl)tetrahydro-3aH-cyclopenta[d][1,3]dioxol-5-amine)), NC98-5(4,7,13-tris(3-oxo-3-(undecylamino)propyl)-N1,N16-diundecyl-4,7,10,13-tetraazahexadecane-1,16-diamide),DODAP (1,2-dioleyl-3-dimethylammonium propane), HGT4003 (WO 2012/170889,the teachings of which are incorporated herein by reference in theirentirety), ICE (WO 2011/068810, the teachings of which are incorporatedherein by reference in their entirety), HGT5000 (international patentpublication WO/2013/149140, the teachings of which are incorporatedherein by reference in their entirety) or HGT5001 (cis or trans)(WO/2013/149140), aminoalcohol lipidoids such as those disclosed inWO2010/053572, DOTAP (1,2-dioleyl-3-trimethylammonium propane), DOTMA(1,2-di-O-octadecenyl-3-trimethylammonium propane), DLinDMA (Heyes, J.;Palmer, L.; Bremner, K.; MacLachlan, I. “Cationic lipid saturationinfluences intracellular delivery of encapsulated nucleic acids” J.Contr. Rel. 2005, 107, 276-287), DLin-KC2-DMA (Semple, S. C. et al.“Rational Design of Cationic Lipids for siRNA Delivery” Nature Biotech.2010, 28, 172-176), C12-200 (Love, K. T. et al. “Lipid-like materialsfor low-dose in vivo gene silencing” PNAS 2010, 107, 1864-1869).

Non-Cationic/Helper Lipids

In some embodiments, provided liposomes contain one or more non-cationic(“helper”) lipids. As used herein, the phrase “non-cationic lipid”refers to any neutral, zwitterionic or anionic lipid. As used herein,the phrase “anionic lipid” refers to any of a number of lipid speciesthat carry a net negative charge at a selected H, such as physiologicalpH. Non-cationic lipids include, but are not limited to,distearoylphosphatidylcholine (DSPC), dioleoylphosphatidylcholine(DOPC), dipalmitoylphosphatidylcholine (DPPC),dioleoylphosphatidylglycerol (DOPG), dipalmitoylphosphatidylglycerol(DPPG), dioleoylphosphatidylethanolamine (DOPE),palmitoyloleoylphosphatidylcholine (POPC),palmitoyloleoyl-phosphatidylethanolamine (POPE),dioleoyl-phosphatidylethanolamine4-(N-maleimidomethyl)-cyclohexane-1-carboxylate (DOPE-mal), dipalmitoylphosphatidyl ethanolamine (DPPE), dimyristoylphosphoethanolamine (DMPE),distearoyl-phosphatidylethanolamine (DSPE), 16-O-monomethyl PE,16-O-dimethyl PE, 18-1-trans PE,1-stearoyl-2-oleoyl-phosphatidyethanolamine (SOPE), or a mixturethereof.

In some embodiments, such non-cationic lipids may be used alone, but arepreferably used in combination with other excipients, for example,cationic lipids. In some embodiments, the non-cationic lipid maycomprise a molar ratio of about 5% to about 90%, or about 10% to about70% of the total lipid present in a liposome. In some embodiments, anon-cationic lipid is a neutral lipid, i.e., a lipid that does not carrya net charge in the conditions under which the composition is formulatedand/or administered. In some embodiments, the percentage of non-cationiclipid in a liposome may be greater than 5%, greater than 10%, greaterthan 20%, greater than 30%, or greater than 40%.

Cholesterol-Based Lipids

In some embodiments, provided liposomes comprise one or morecholesterol-based lipids. For example, suitable cholesterol-basedcationic lipids include, for example, DC-Chol(N,N-dimethyl-N-ethylcarboxamidocholesterol),1,4-bis(3-N-oleylamino-propyl)piperazine (Gao, et al. Biochem. Biophys.Res. Comm. 179, 280 (1991); Wolf et al. BioTechniques 23, 139 (1997);U.S. Pat. No. 5,744,335), or ICE. In some embodiments, thecholesterol-based lipid may comprise a molar ration of about 2% to about30%, or about 5% to about 20% of the total lipid present in a liposome.In some embodiments, The percentage of cholesterol-based lipid in thelipid nanoparticle may be greater than 5, %, 10%, greater than 20%,greater than 30%, or greater than 40%.

PEGylated Lipids

In some embodiments, provided liposomes comprise one or more PEGylatedlipids. For example, the use of polyethylene glycol (PEG)-modifiedphospholipids and derivatized lipids such as derivatized ceramides(PEG-CER), including N-Octanoyl-Sphingosine-1-[Succinyl(MethoxyPolyethylene Glycol)-2000] (C8 PEG-2000 ceramide) is also contemplatedby the present invention in combination with one or more of the cationicand, in some embodiments, other lipids together which comprise theliposome. Contemplated PEG-modified lipids include, but are not limitedto, a polyethylene glycol chain of up to 5 kDa in length covalentlyattached to a lipid with alkyl chain(s) of C₆-C₂₀ length. In someembodiments, a PEG-modified or PEGylated lipid is PEGylated cholesterolor PEG-2K. The addition of such components may prevent complexaggregation and may also provide a means for increasing circulationlifetime and increasing the delivery of the lipid-nucleic acidcomposition to the target cell, (Klibanov et al. (1990) FEBS Letters,268 (1): 235-237), or they may be selected to rapidly exchange out ofthe formulation in vivo (see U.S. Pat. No. 5,885,613).

In some embodiments, particularly useful exchangeable lipids arePEG-ceramides having shorter acyl chains (e.g., C₁₄ or C₁₈). ThePEG-modified phospholipid and derivatized lipids of the presentinvention may comprise a molar ratio from about 0% to about 15%, about0.5% to about 15%, about 1% to about 15%, about 4% to about 10%, orabout 2% of the total lipid present in the liposome.

According to various embodiments, the selection of second or additionalcationic lipids, non-cationic lipids and/or PEG-modified lipids whichcomprise the lipid nanoparticle, as well as the relative molar ratio ofsuch lipids to each other, is based upon the characteristics of theselected lipid(s), the nature of the intended target cells, thecharacteristics of the mRNA to be delivered. Additional considerationsinclude, for example, the saturation of the alkyl chain, as well as thesize, charge, pH, pKa, fusogenicity and toxicity of the selectedlipid(s). Thus the molar ratios may be adjusted accordingly. In someembodiments, the percentage of PEG-modified lipid in a liposome may begreater than 1%, greater than 2%, greater than 5%, greater than 10%, orgreater than 15%.

Polymers

In some embodiments, a suitable liposome according to the presentinvention further includes a polymer, in combination with one or morecationic lipids as described and, in some embodiments, other carriersincluding various lipids described herein. Thus, in some embodiments,liposomal delivery vehicles, as used herein, also encompass polymercontaining nanoparticles. Suitable polymers may include, for example,polyacrylates, polyalkycyanoacrylates, polylactide,polylactide-polyglycolide copolymers, polycaprolactones, dextran,albumin, gelatin, alginate, collagen, chitosan, cyclodextrins,protamine, PEGylated protamine, PLL, PEGylated PLL and polyethylenimine(PEI). When PEI is present, it may be branched PEI of a molecular weightranging from 10 to 40 kDA, e.g., 25 kDa branched PEI (Sigma #408727).

Therapeutic Agents

The present invention may be used to delivery any therapeutic agents.Specifically, any therapeutic agents to be administered to a subject maybe delivered using the complexes, picoparticles, nanoparticles,microparticles, micelles, or liposomes, described herein. The agent maybe an organic molecule (e.g., a therapeutic agent, a drug), inorganicmolecule, nucleic acid, protein, amino acid, peptide, polypeptide,polynucleotide, targeting agent, isotopically labeled organic orinorganic molecule, vaccine, immunological agent, etc. In certainembodiments of the present invention, the agent to be delivered may be amixture of agents.

In certain embodiments, the therapeutic agents are organic moleculeswith pharmaceutical activity, e.g., a drug. In certain embodiments, thedrug is an antibiotic, anti-viral agent, anesthetic, steroidal agent,anti-inflammatory agent, anti-neoplastic agent, anti-cancer agent,antigen, vaccine, antibody, decongestant, antihypertensive, sedative,birth control agent, progestational agent, anti-cholinergic, analgesic,anti-depressant, anti-psychotic, I3-adrenergic blocking agent, diuretic,cardiovascular active agent, vasoactive agent, non-steroidalanti-inflammatory agent, nutritional agent, etc.

Diagnostic agents include gases; metals; commercially available imagingagents used in positron emissions tomography (PET), computer assistedtomography (CAT), single photon emission computerized tomography, x-ray,fluoroscopy, and magnetic resonance imaging (MRI); and contrast agents.Examples of suitable materials for use as contrast agents in MRI includegadolinium chelates, as well as iron, magnesium, manganese, copper, andchromium. Examples of materials useful for CAT and x-ray imaging includeiodine based materials.

Therapeutic and prophylactic agents include, but are not limited to,antibiotics, nutritional supplements, and vaccines. Vaccines maycomprise isolated proteins or peptides, inactivated organisms andviruses, dead organisms and viruses, genetically altered organisms orviruses, and cell extracts.

Polynucleotides

The present invention may be used to deliver any polynucleotide. Incertain embodiments, the polynucleotide is an interfering RNA (RNAi).The phenomenon of RNAi is discussed in greater detail, for example, inthe following references: Elbashir et al., 2001, Genes Dev., 15:188;Fire et al., 1998, Nature, 391:806; Tabara et al., 1999, Cell, 99:123;Hammond et al., Nature, 2000, 404:293; Zamore et al., 2000, Cell,101:25; Chakraborty, 2007, Curr. Drug Targets, 8:469; and Morris andRossi, 2006, Gene Ther., 13:553. In certain embodiments, thepolynucleotide is a dsRNA (double-stranded RNA). In certain embodiments,the polynucleotide is an siRNA (short interfering RNA). In certainembodiments, the polynucleotide is an shRNA (short hairpin RNA). Incertain embodiments, the polynucleotide is an miRNA (micro RNA). MicroRNAs (miRNAs) are genomically encoded non-coding RNAs of about 21-23nucleotides in length that help regulate gene expression, particularlyduring development. See, e.g., Bartel, 2004, Cell, 116:281; Novina andSharp, 2004, Nature, 430:161; and U.S. Patent Publication 2005/0059005;also reviewed in Wang and Li, 2007, Front. Biosci., 12:3975; and Zhao,2007, Trends Biochem. Sci., 32:189. In certain embodiments, thepolynucleotide is an antisense RNA.

In certain embodiments, the polynucleotide may be provided as anantisense agent or RNA interference (RNAi). See, e.g., Fire et al.,Nature 391:806-811, 1998. Antisense therapy is meant to include, e.g.,administration or in situ provision of single- or double-strandedoligonucleotides or their derivatives which specifically hybridize,e.g., bind, under cellular conditions, with cellular mRNA and/or genomicDNA, or mutants thereof, so as to inhibit expression of the encodedprotein, e.g., by inhibiting transcription and/or translation. See,e.g., Crooke “Molecular mechanisms of action of antisense drugs”Biochim. Biophys. Acta 1489(1):31-44, 1999; Crooke “Evaluating themechanism of action of antiproliferative antisense drugs” AntisenseNucleic Acid Drug Dev. 10(2):123-126, discussion 127, 2000; Methods inEnzymology volumes 313-314, 1999. The binding may be by conventionalbase pair complementarity, or, for example, in the case of binding toDNA duplexes, through specific interactions in the major groove of thedouble helix (i.e., triple helix formation). See, e.g., Chan et al., J.Mol. Med. 75(4):267-282, 1997.

In some embodiments, dsRNA, siRNA, shRNA, miRNA, antisense RNA, and/orRNAi can be designed and/or predicted using one or more of a largenumber of available algorithms. To give but a few examples, thefollowing resources can be utilized to design and/or predictpolynucleotides: algorithms found at Alnylum Online, Dharmacon Online,OligoEngine Online, Molecula Online, Ambion Online, BioPredsi Online,RNAi Web Online, Chang Bioscience Online, Invitrogen Online, LentiWebOnline GenScript Online, Protocol Online; Reynolds et al., 2004, Nat.Biotechnol., 22:326; Naito et al., 2006, Nucleic Acids Res., 34:W448; Liet al., 2007, RNA, 13:1765; Yiu et al., 2005, Bioinformatics, 21:144;and Jia et al., 2006, BMC Bioinformatics, 7: 271.

The polynucleotides may be of any size or sequence, and they may besingle- or double-stranded. In certain embodiments, the polynucleotideis greater than 100 base pairs long. In certain embodiments, thepolynucleotide is greater than 1000 base pairs long and may be greaterthan 10,000 base pairs long. The polynucleotide may be provided by anymeans known in the art. In certain embodiments, the polynucleotide hasbeen engineered using recombinant techniques. See, e.g., Ausubel et al.,Current Protocols in Molecular Biology (John Wiley & Sons, Inc., NewYork, 1999); Molecular Cloning: A Laboratory Manual, 2nd Ed., ed. bySambrook, Fritsch, and Maniatis (Cold Spring Harbor Laboratory Press:1989). The polynucleotide may also be obtained from natural sources andpurified from contaminating components found normally in nature. Thepolynucleotide may also be chemically synthesized in a laboratory. Incertain embodiments, the polynucleotide is synthesized using standardsolid phase chemistry.

The polynucleotide may be modified by chemical or biological means. Incertain embodiments, these modifications lead to increased stability ofthe polynucleotide. Modifications include methylation, phosphorylation,end-capping, etc. mRNA

The present invention can be used to deliver any mRNA. mRNA is typicallythought of as the type of RNA that carries information from DNA to theribosome. The existence of mRNA is usually very brief and includesprocessing and translation, followed by degradation. Typically, ineukaryotic organisms, mRNA processing comprises the addition of a “cap”on the N-terminal (5′) end, and a “tail” on the C-terminal (3′) end. Atypical cap is a 7-methylguanosine cap, which is a guanosine that islinked through a 5′-5′-triphosphate bond to the first transcribednucleotide. The presence of the cap is important in providing resistanceto nucleases found in most eukaryotic cells. The tail is typically apolyadenylation event whereby a polyadenylyl moiety is added to the 3′end of the mRNA molecule. The presence of this “tail” serves to protectthe mRNA from exonuclease degradation. Messenger RNA typically istranslated by the ribosomes into a series of amino acids that make up aprotein.

Any mRNA capable of being translated into one or more peptides (e.g.,proteins) or peptide fragments is contemplated as within the scope ofthe present invention. In some embodiments, an mRNA encodes one or morenaturally occurring peptides. In some embodiments, an mRNA encodes oneor more modified or non-natural peptides.

In some embodiments an mRNA encodes an intracellular protein. In someembodiments, an mRNA encodes a cytosolic protein. In some embodiments,an mRNA encodes a protein associated with the actin cytoskeleton. Insome embodiments, an mRNA encodes a protein associated with the plasmamembrane. In some specific embodiments, an mRNA encodes a transmembraneprotein. In some specific embodiments an mRNA encodes an ion channelprotein. In some embodiments, an mRNA encodes a perinuclear protein. Insome embodiments, an mRNA encodes a nuclear protein. In some specificembodiments, an mRNA encodes a transcription factor. In someembodiments, an mRNA encodes a chaperone protein. In some embodiments,an mRNA encodes an intracellular enzyme (e.g., mRNA encoding an enzymeassociated with urea cycle or lysosomal storage metabolic disorders). Insome embodiments, an mRNA encodes a protein involved in cellularmetabolism, DNA repair, transcription and/or translation. In someembodiments, an mRNA encodes an extracellular protein. In someembodiments, an mRNA encodes a protein associated with the extracellularmatrix. In some embodiments an mRNA encodes a secreted protein. Inspecific embodiments, an mRNA used in the composition and methods of theinvention may be used to express functional proteins or enzymes that areexcreted or secreted by one or more target cells into the surroundingextracellular fluid (e.g., mRNA encoding hormones and/orneurotransmitters).

Synthesis of mRNA

mRNAs according to the present invention may be synthesized according toany of a variety of known methods. For example, mRNAs according to thepresent invention may be synthesized via in vitro transcription (IVT).Briefly, IVT is typically performed with a linear or circular DNAtemplate containing a promoter, a pool of ribonucleotide triphosphates,a buffer system that may include DTT and magnesium ions, and anappropriate RNA polymerase (e.g., T3, T7 or SP6 RNA polymerase), DNAseI, pyrophosphatase, and/or RNAse inhibitor. The exact conditions willvary according to the specific application.

In some embodiments, for the preparation of mRNA according to theinvention, a DNA template is transcribed in vitro. A suitable DNAtemplate typically has a promoter, for example a T3, T7 or SP6 promoter,for in vitro transcription, followed by desired nucleotide sequence fordesired mRNA and a termination signal.

Desired mRNA sequence(s) according to the invention may be determinedand incorporated into a DNA template using standard methods. Forexample, starting from a desired amino acid sequence (e.g., an enzymesequence), a virtual reverse translation is carried out based on thedegenerated genetic code. Optimization algorithms may then be used forselection of suitable codons. Typically, the G/C content can beoptimized to achieve the highest possible G/C content on one hand,taking into the best possible account the frequency of the tRNAsaccording to codon usage on the other hand. The optimized RNA sequencecan be established and displayed, for example, with the aid of anappropriate display device and compared with the original (wild-type)sequence. A secondary structure can also be analyzed to calculatestabilizing and destabilizing properties or, respectively, regions ofthe RNA.

Modified mRNA

In some embodiments, mRNA according to the present invention may besynthesized as unmodified or modified mRNA. Typically, mRNAs aremodified to enhance stability. Modifications of mRNA can include, forexample, modifications of the nucleotides of the RNA. An modified mRNAaccording to the invention can thus include, for example, backbonemodifications, sugar modifications or base modifications. In someembodiments, mRNAs may be synthesized from naturally occurringnucleotides and/or nucleotide analogues (modified nucleotides)including, but not limited to, purines (adenine (A), guanine (G)) orpyrimidines (thymine (T), cytosine (C), uracil (U)), and as modifiednucleotides analogues or derivatives of purines and pyrimidines, such ase.g. 1-methyl-adenine, 2-methyl-adenine,2-methylthio-N-6-isopentenyl-adenine, N6-methyl-adenine,N6-isopentenyl-adenine, 2-thio-cytosine, 3-methyl-cytosine,4-acetyl-cytosine, 5-methyl-cytosine, 2,6-diaminopurine,1-methyl-guanine, 2-methyl-guanine, 2,2-dimethyl-guanine,7-methyl-guanine, inosine, 1-methyl-inosine, pseudouracil (5-uracil),dihydro-uracil, 2-thio-uracil, 4-thio-uracil,5-carboxymethylamino-methyl-2-thio-uracil,5-(carboxyhydroxymethyl)-uracil, 5-fluoro-uracil, 5-bromo-uracil,5-carboxymethylaminomethyl-uracil, 5-methyl-2-thio-uracil,5-methyl-uracil, N-uracil-5-oxy-acetic acid methyl ester,5-methylaminomethyl-uracil, 5-methoxyaminomethyl-2-thio-uracil,5′-methoxycarbonylmethyl-uracil, 5-methoxy-uracil, uracil-5-oxyaceticacid methyl ester, uracil-5-oxyacetic acid (v), 1-methyl-pseudouracil,queosine, β-D-mannosyl-queosine, wybutosine, and phosphoramidates,phosphorothioates, peptide nucleotides, methylphosphonates,7-deazaguanosine, 5-methylcytosine and inosine. The preparation of suchanalogues is known to a person skilled in the art e.g. from the U.S.Pat. Nos. 4,373,071, 4,401,796, 4,415,732, 4,458,066, 4,500,707,4,668,777, 4,973,679, 5,047,524, 5,132,418, 5,153,319, 5,262,530 and5,700,642, the disclosures of which are incorporated by reference intheir entirety.

In some embodiments, mRNAs (e.g., enzyme encoding mRNAs) may contain RNAbackbone modifications. Typically, a backbone modification is amodification in which the phosphates of the backbone of the nucleotidescontained in the RNA are modified chemically. Exemplary backbonemodifications typically include, but are not limited to, modificationsfrom the group consisting of methylphosphonates, methylphosphoramidates,phosphoramidates, phosphorothioates (e.g. cytidine5′-O-(1-thiophosphate)), boranophosphates, positively chargedguanidinium groups etc., which means by replacing the phosphodiesterlinkage by other anionic, cationic or neutral groups.

In some embodiments, mRNAs (e.g., enzyme encoding mRNAs) may containsugar modifications. A typical sugar modification is a chemicalmodification of the sugar of the nucleotides it contains including, butnot limited to, sugar modifications chosen from the group consisting of2′-deoxy-2′-fluoro-oligoribonucleotide (2′-fluoro-2′-deoxycytidine5′-triphosphate, 2′-fluoro-2′-deoxyuridine 5′-triphosphate),2′-deoxy-2′-deamine-oligoribonucleotide (2′-amino-2′-deoxycytidine5′-triphosphate, 2′-amino-2′-deoxyuridine 5′-triphosphate),2′-O-alkyloligoribonucleotide, 2′-deoxy-2′-C-alkyloligoribonucleotide(2′-O-methylcytidine 5′-triphosphate, 2′-methyluridine 5′-triphosphate),2′-C-alkyloligoribonucleotide, and isomers thereof (2′-ara-cytidine5′-triphosphate, 2′-arauridine 5′-triphosphate), or azidotriphosphates(2′-azido-2′-deoxy-cytidine 5′-triphosphate, 2′-azido-2′-deoxyuridine5′-triphosphate).

In some embodiments, mRNAs (e.g., enzyme encoding mRNAs) may containmodifications of the bases of the nucleotides (base modifications). Amodified nucleotide which contains a base modification is also called abase-modified nucleotide. Examples of such base-modified nucleotidesinclude, but are not limited to, 2-amino-6-chloropurine riboside5′-triphosphate, 2-aminoadenosine 5′-triphosphate, 2-thiocytidine5′-triphosphate, 2-thiouridine 5′-triphosphate, 4-thiouridine5′-triphosphate, 5-aminoallylcytidine 5′-triphosphate,5-aminoallyl-uridine 5′-triphosphate, 5-bromocytidine 5′-triphosphate,5-bromouridine 5′-triphosphate, 5-iodo-cytidine 5′-triphosphate,5-iodouridine 5′-triphosphate, 5-methylcytidine 5′-triphosphate,5-methyluridine 5′-triphosphate, 6-azacytidine 5′-triphosphate,6-azauridine 5′-triphosphate, 6-chloropurine riboside 5′-triphosphate,7-deazaadenosine 5′-triphosphate, 7-deazaguanosine 5′-triphosphate,8-azaadenosine 5′-triphosphate, 8-azidoadenosine 5′-triphosphate,benzimidazole riboside 5′-triphosphate, N1-methyladenosine5′-triphosphate, N1-methylguanosine 5′-triphosphate, N6-methyladenosine5′-triphosphate, 06-methylguanosine 5′-triphosphate, pseudo-uridine5′-triphosphate, puromycin 5′-triphosphate or xanthosine5′-triphosphate.

Cap Structure

Typically, mRNA synthesis includes the addition of a “cap” on theN-terminal (5′) end, and a “tail” on the C-terminal (3′) end. Thepresence of the cap is important in providing resistance to nucleasesfound in most eukaryotic cells. The presence of a “tail” serves toprotect the mRNA from exonuclease degradation.

Thus, in some embodiments, mRNAs (e.g., enzyme encoding mRNAs) include a5′ cap structure. A 5′ cap is typically added as follows: first, an RNAterminal phosphatase removes one of the terminal phosphate groups fromthe 5′ nucleotide, leaving two terminal phosphates; guanosinetriphosphate (GTP) is then added to the terminal phosphates via aguanylyl transferase, producing a 5′5′5 triphosphate linkage; and the7-nitrogen of guanine is then methylated by a methyltransferase.Examples of cap structures include, but are not limited to, m7G(5′)ppp(5′(A,G(5′)ppp(5′)A and G(5′)ppp(5′)G.

In some embodiments, naturally occurring cap structures comprise a7-methyl guanosine that is linked via a triphosphate bridge to the5′-end of the first transcribed nucleotide, resulting in a dinucleotidecap of m⁷G(5′)ppp(5′)N, where N is any nucleoside. In vivo, the cap isadded enzymatically. The cap is added in the nucleus and is catalyzed bythe enzyme guanylyl transferase. The addition of the cap to the 5′terminal end of RNA occurs immediately after initiation oftranscription. The terminal nucleoside is typically a guanosine, and isin the reverse orientation to all the other nucleotides, i.e.,G(5′)ppp(5′)GpNpNp.

A common cap for mRNA produced by in vitro transcription ism⁷G(5′)ppp(5′)G, which has been used as the dinucleotide cap intranscription with T7 or SP6 RNA polymerase in vitro to obtain RNAshaving a cap structure in their 5′-termini. The prevailing method forthe in vitro synthesis of capped mRNA employs a pre-formed dinucleotideof the form m⁷G(5′)ppp(5′)G (“m⁷GpppG”) as an initiator oftranscription.

To date, a usual form of a synthetic dinucleotide cap used in in vitrotranslation experiments is the Anti-Reverse Cap Analog (“ARCA”) ormodified ARCA, which is generally a modified cap analog in which the 2′or 3′ OH group is replaced with —OCH₃.

Additional cap analogs include, but are not limited to, chemicalstructures selected from the group consisting of m⁷GpppG, m⁷GpppA,m⁷GpppC; unmethylated cap analogs (e.g., GpppG); dimethylated cap analog(e.g., m^(2,7)GpppG), trimethylated cap analog (e.g., m^(2,2,7)GpppG),dimethylated symmetrical cap analogs (e.g., m⁷Gpppm⁷G), or anti reversecap analogs (e.g., ARCA; m^(7,2′Ome)GpppG, m^(72′d)GpppG,m^(7,3′Ome)GpppG, m^(7,3′d)GpppG and their tetraphosphate derivatives)(see, e.g., Jemielity, J. et al., “Novel ‘anti-reverse’ cap analogs withsuperior translational properties”, RNA, 9: 1108-1122 (2003)).

In some embodiments, a suitable cap is a 7-methyl guanylate (“m⁷G”)linked via a triphosphate bridge to the 5′-end of the first transcribednucleotide, resulting in m⁷G(5′)ppp(5′)N, where N is any nucleoside. Apreferred embodiment of a m⁷G cap utilized in embodiments of theinvention is m⁷G(5′)ppp(5′)G.

In some embodiments, the cap is a Cap0 structure. Cap0 structures lack a2′-O-methyl residue of the ribose attached to bases 1 and 2. In someembodiments, the cap is a Cap1 structure. Cap1 structures have a2′-O-methyl residue at base 2. In some embodiments, the cap is a Cap2structure. Cap2 structures have a 2′-O-methyl residue attached to bothbases 2 and 3.

A variety of m⁷G cap analogs are known in the art, many of which arecommercially available. These include the m⁷GpppG described above, aswell as the ARCA 3′-OCH₃ and 2′-OCH₃ cap analogs (Jemielity, J. et al.,RNA, 9: 1108-1122 (2003)). Additional cap analogs for use in embodimentsof the invention include N7-benzylated dinucleoside tetraphosphateanalogs (described in Grudzien, E. et al., RNA, 10: 1479-1487 (2004)),phosphorothioate cap analogs (described in Grudzien-Nogalska, E., etal., RNA, 13: 1745-1755 (2007)), and cap analogs (including biotinylatedcap analogs) described in U.S. Pat. Nos. 8,093,367 and 8,304,529,incorporated by reference herein.

Tail Structure

Typically, the presence of a “tail” serves to protect the mRNA fromexonuclease degradation. The poly A tail is thought to stabilize naturalmessengers and synthetic sense RNA. Therefore, in certain embodiments along poly A tail can be added to an mRNA molecule thus rendering the RNAmore stable. Poly A tails can be added using a variety of art-recognizedtechniques. For example, long poly A tails can be added to synthetic orin vitro transcribed RNA using poly A polymerase (Yokoe, et al. NatureBiotechnology. 1996; 14: 1252-1256). A transcription vector can alsoencode long poly A tails. In addition, poly A tails can be added bytranscription directly from PCR products. Poly A may also be ligated tothe 3′ end of a sense RNA with RNA ligase (see, e.g., Molecular CloningA Laboratory Manual, 2nd Ed., ed. by Sambrook, Fritsch and Maniatis(Cold Spring Harbor Laboratory Press: 1991 edition)).

In some embodiments, mRNAs (e.g., enzyme encoding mRNAs) include a 3′poly(A) tail structure. Typically, the length of the poly A tail can beat least about 10, 50, 100, 200, 300, 400 at least 500 nucleotides. Insome embodiments, a poly-A tail on the 3′ terminus of mRNA typicallyincludes about 10 to 300 adenosine nucleotides (e.g., about 10 to 200adenosine nucleotides, about 10 to 150 adenosine nucleotides, about 10to 100 adenosine nucleotides, about 20 to 70 adenosine nucleotides, orabout 20 to 60 adenosine nucleotides). In some embodiments, mRNAsinclude a 3′ poly(C) tail structure. A suitable poly-C tail on the 3′terminus of mRNA typically include about 10 to 200 cytosine nucleotides(e.g., about 10 to 150 cytosine nucleotides, about 10 to 100 cytosinenucleotides, about 20 to 70 cytosine nucleotides, about 20 to 60cytosine nucleotides, or about 10 to 40 cytosine nucleotides). Thepoly-C tail may be added to the poly-A tail or may substitute the poly-Atail.

In some embodiments, the length of the poly A or poly C tail is adjustedto control the stability of a modified sense mRNA molecule of theinvention and, thus, the transcription of protein. For example, sincethe length of the poly A tail can influence the half-life of a sensemRNA molecule, the length of the poly A tail can be adjusted to modifythe level of resistance of the mRNA to nucleases and thereby control thetime course of polynucleotide expression and/or polypeptide productionin a target cell.

5′ and 3′ Untranslated Region

In some embodiments, mRNAs include a 5′ and/or 3′ untranslated region.In some embodiments, a 5′ untranslated region includes one or moreelements that affect an mRNA's stability or translation, for example, aniron responsive element. In some embodiments, a 5′ untranslated regionmay be between about 50 and 500 nucleotides in length.

In some embodiments, a 3′ untranslated region includes one or more of apolyadenylation signal, a binding site for proteins that affect anmRNA's stability of location in a cell, or one or more binding sites formiRNAs. In some embodiments, a 3′ untranslated region may be between 50and 500 nucleotides in length or longer.

Exemplary 3′ and/or 5′ UTR sequences can be derived from mRNA moleculeswhich are stable (e.g., globin, actin, GAPDH, tubulin, histone, orcitric acid cycle enzymes) to increase the stability of the sense mRNAmolecule. For example, a 5′ UTR sequence may include a partial sequenceof a CMV immediate-early 1 (IE1) gene, or a fragment thereof to improvethe nuclease resistance and/or improve the half-life of thepolynucleotide. Also contemplated is the inclusion of a sequenceencoding human growth hormone (hGH), or a fragment thereof to the 3′ endor untranslated region of the polynucleotide (e.g., mRNA) to furtherstabilize the polynucleotide. Generally, these modifications improve thestability and/or pharmacokinetic properties (e.g., half-life) of thepolynucleotide relative to their unmodified counterparts, and include,for example modifications made to improve such polynucleotides'resistance to in vivo nuclease digestion.

According to various embodiments, any size mRNA may be encapsulated byprovided liposomes. In some embodiments, the provided liposomes mayencapsulate mRNA of greater than about 0.5 kb, 1 kb, 1.5 kb, 2 kb, 2.5kb, 3 kb, 3.5 kb, 4 kb, 4.5 kb, or 5 kb in length.

Liposomes

The liposomes for use in provided compositions can be prepared byvarious techniques which are presently known in the art. For example,multilamellar vesicles (MLV) may be prepared according to conventionaltechniques, such as by depositing a selected lipid on the inside wall ofa suitable container or vessel by dissolving the lipid in an appropriatesolvent, and then evaporating the solvent to leave a thin film on theinside of the vessel or by spray drying. An aqueous phase may then addedto the vessel with a vortexing motion which results in the formation ofMLVs. Uni-lamellar vesicles (ULV) can then be formed by homogenization,sonication or extrusion of the multi-lamellar vesicles. In addition,unilamellar vesicles can be formed by detergent removal techniques.

In certain embodiments, provided compositions comprise a liposomewherein an agent, such as a nucleic acid e.g., mRNA, is associated onboth the surface of the liposome and encapsulated within the sameliposome. For example, during preparation of the compositions of thepresent invention, cationic liposomes may associate with the mRNAthrough electrostatic interactions. For example, during preparation ofthe compositions of the present invention, cationic liposomes mayassociate with the mRNA through electrostatic interactions.

In some embodiments, the compositions and methods of the inventioncomprise mRNA encapsulated in a liposome. In some embodiments, the oneor more mRNA species may be encapsulated in the same liposome. In someembodiments, the one or more mRNA species may be encapsulated indifferent liposomes. In some embodiments, the mRNA is encapsulated inone or more liposomes, which differ in their lipid composition, molarratio of lipid components, size, charge (Zeta potential), targetingligands and/or combinations thereof. In some embodiments, the one ormore liposome may have a different composition of cationic lipids,neutral lipid, PEG-modified lipid and/or combinations thereof. In someembodiments the one or more liposomes may have a different molar ratioof cationic lipid, neutral lipid, cholesterol and PEG-modified lipidused to create the liposome.

The process of incorporation of a desired therapeutic agent, such as anucleic acid (e.g., mRNA), into a liposome is often referred to as“loading”. Exemplary methods are described in Lasic, et al., FEBS Lett.,312: 255-258, 1992, which is incorporated herein by reference. Theliposome-incorporated nucleic acids may be completely or partiallylocated in the interior space of the liposome, within the bilayermembrane of the liposome, or associated with the exterior surface of theliposome membrane. The incorporation of a nucleic acid into liposomes isalso referred to herein as “encapsulation” wherein the nucleic acid isentirely contained within the interior space of the liposome. Thepurpose of incorporating a mRNA into a transfer vehicle, such as aliposome, is often to protect the nucleic acid from an environment whichmay contain enzymes or chemicals that degrade nucleic acids and/orsystems or receptors that cause the rapid excretion of the nucleicacids. Accordingly, in some embodiments, a suitable delivery vehicle iscapable of enhancing the stability of the mRNA contained therein and/orfacilitate the delivery of mRNA to the target cell or tissue.

Liposome Size

Suitable liposomes in accordance with the present invention may be madein various sizes. In some embodiments, provided liposomes may be madesmaller than previously known mRNA encapsulating liposomes. In someembodiments, decreased size of liposomes is associated with moreefficient delivery of mRNA. Selection of an appropriate liposome sizemay take into consideration the site of the target cell or tissue and tosome extent the application for which the liposome is being made.

In some embodiments, an appropriate size of liposome is selected tofacilitate systemic distribution of antibody encoded by the mRNA. Insome embodiments, it may be desirable to limit transfection of the mRNAto certain cells or tissues. For example, to target hepatocytes aliposome may be sized such that its dimensions are smaller than thefenestrations of the endothelial layer lining hepatic sinusoids in theliver; in such cases the liposome could readily penetrate suchendothelial fenestrations to reach the target hepatocytes.

Alternatively or additionally, a liposome may be sized such that thedimensions of the liposome are of a sufficient diameter to limit orexpressly avoid distribution into certain cells or tissues. For example,a liposome may be sized such that its dimensions are larger than thefenestrations of the endothelial layer lining hepatic sinusoids tothereby limit distribution of the liposomes to hepatocytes.

In some embodiments, a suitable liposome has a size of or less thanabout 500 nm, 450 nm, 400 nm, 350 nm, 300 nm, 250 nm, 200 nm, 150 nm,125 nm, 110 nm, 100 nm, 95 nm, 90 nm, 85 nm, 80 nm, 75 nm, 70 nm, 65 nm,60 nm, 55 nm, or 50 nm. In some embodiments, a suitable liposome has asize no greater than about 250 nm (e.g., no greater than about 225 nm,200 nm, 175 nm, 150 nm, 125 nm, 100 nm, 75 nm, or 50 nm). In someembodiments, a suitable liposome has a size ranging from about 10-250 nm(e.g., ranging from about 10-225 nm, 10-200 nm, 10-175 nm, 10-150 nm,10-125 nm, 10-100 nm, 10-75 nm, or 10-50 nm). In some embodiments, asuitable liposome has a size ranging from about 100-250 nm (e.g.,ranging from about 100-225 nm, 100-200 nm, 100-175 nm, 100-150 nm). Insome embodiments, a suitable liposome has a size ranging from about10-100 nm (e.g., ranging from about 10-90 nm, 10-80 nm, 10-70 nm, 10-60nm, or 10-50 nm).

A variety of alternative methods known in the art are available forsizing of a population of liposomes. One such sizing method is describedin U.S. Pat. No. 4,737,323, incorporated herein by reference. Sonicatinga liposome suspension either by bath or probe sonication produces aprogressive size reduction down to small ULV less than about 0.05microns in diameter. Homogenization is another method that relies onshearing energy to fragment large liposomes into smaller ones. In atypical homogenization procedure, MLV are recirculated through astandard emulsion homogenizer until selected liposome sizes, typicallybetween about 0.1 and 0.5 microns, are observed. The size of theliposomes may be determined by quasi-electric light scattering (QELS) asdescribed in Bloomfield, Ann. Rev. Biophys. Bioeng., 10:421-150 (1981),incorporated herein by reference. Average liposome diameter may bereduced by sonication of formed liposomes. Intermittent sonicationcycles may be alternated with QELS assessment to guide efficientliposome synthesis.

Pharmaceutical Compositions

To facilitate delivery of an agent, such as a nucleic acid e.g., mRNA,and/or expression of mRNA in vivo, delivery vehicles such as liposomescan be formulated in combination with one or more additional nucleicacids, carriers, targeting ligands or stabilizing reagents, or inpharmacological compositions where it is mixed with suitable excipients.Techniques for formulation and administration of drugs may be found in“Remington's Pharmaceutical Sciences,” Mack Publishing Co., Easton, Pa.,latest edition.

Provided liposomally-encapsulated agents, such as a nucleic acid e.g.,mRNA and compositions containing the same, may be administered and dosedin accordance with current medical practice, taking into account theclinical condition of the subject, the site and method ofadministration, the scheduling of administration, the subject's age,sex, body weight and other factors relevant to clinicians of ordinaryskill in the art. The “effective amount” for the purposes herein may bedetermined by such relevant considerations as are known to those ofordinary skill in experimental clinical research, pharmacological,clinical and medical arts. In some embodiments, the amount administeredis effective to achieve at least some stabilization, improvement orelimination of symptoms and other indicators as are selected asappropriate measures of disease progress, regression or improvement bythose of skill in the art. For example, a suitable amount and dosingregimen is one that causes at least transient protein (e.g., enzyme)production.

Suitable routes of administration include, for example, oral, rectal,vaginal, transmucosal, pulmonary including intratracheal or inhaled, orintestinal administration; parenteral delivery, including intradermal,transdermal (topical), intramuscular, subcutaneous, intramedullaryinjections, as well as intrathecal, direct intraventricular,intravenous, intraperitoneal, and/or intranasal administration.

Alternately or additionally, liposomally encapsulated agents, such as anucleic acid e.g., mRNA and compositions of the invention may beadministered in a local rather than systemic manner, for example, viainjection of the pharmaceutical composition directly into a targetedtissue, preferably in a sustained release formulation. Local deliverycan be affected in various ways, depending on the tissue to be targeted.For example, aerosols containing compositions of the present inventioncan be inhaled (for nasal, tracheal, or bronchial delivery);compositions of the present invention can be injected into the site ofinjury, disease manifestation, or pain, for example; compositions can beprovided in lozenges for oral, tracheal, or esophageal application; canbe supplied in liquid, tablet or capsule form for administration to thestomach or intestines, can be supplied in suppository form for rectal orvaginal application; or can even be delivered to the eye by use ofcreams, drops, or even injection. Formulations containing providedcompositions complexed with therapeutic molecules or ligands can even besurgically administered, for example in association with a polymer orother structure or substance that can allow the compositions to diffusefrom the site of implantation to surrounding cells. Alternatively, theycan be applied surgically without the use of polymers or supports.

In some embodiments, provided liposomes and/or compositions areformulated such that they are suitable for extended-release of theagent, e.g., mRNA contained therein. Such extended-release compositionsmay be conveniently administered to a subject at extended dosingintervals. For example, in one embodiment, the compositions of thepresent invention are administered to a subject twice day, daily orevery other day. In a preferred embodiment, the compositions of thepresent invention are administered to a subject twice a week, once aweek, every ten days, every two weeks, every three weeks, or morepreferably every four weeks, once a month, every six weeks, every eightweeks, every other month, every three months, every four months, everysix months, every eight months, every nine months or annually. Alsocontemplated are compositions and liposomes which are formulated fordepot administration (e.g., intramuscularly, subcutaneously,intravitreally) to either deliver or release a mRNA over extendedperiods of time. Preferably, the extended-release means employed arecombined with modifications made to the mRNA to enhance stability.

Also contemplated herein are lyophilized pharmaceutical compositionscomprising one or more of the liposomes disclosed herein and relatedmethods for the use of such compositions as disclosed for example, inInternational Patent Application No. PCT/US2012/041663, filed Jun. 8,2012, Publ. No. WO 2012/170889, the teachings of which are incorporatedherein by reference in their entirety. For example, lyophilizedpharmaceutical compositions according to the invention may bereconstituted prior to administration or can be reconstituted in vivo.For example, a lyophilized pharmaceutical composition can be formulatedin an appropriate dosage form (e.g., an intradermal dosage form such asa disk, rod or membrane) and administered such that the dosage form isrehydrated over time in vivo by the individual's bodily fluids.

Provided liposomes and compositions may be administered to any desiredtissue. In some embodiments, the agent, e.g., mRNA delivered by providedliposomes or compositions is expressed in the tissue in which theliposomes and/or compositions were administered. In some embodiments,the mRNA delivered is expressed in a tissue different from the tissue inwhich the liposomes and/or compositions were administered Exemplarytissues in which delivered mRNA may be delivered and/or expressedinclude, but are not limited to the liver, kidney, heart, spleen, serum,brain, skeletal muscle, lymph nodes, skin, and/or cerebrospinal fluid.

According to various embodiments, the timing of expression of deliveredagents, e.g., mRNAs, can be tuned to suit a particular medical need. Insome embodiments, the expression of the protein encoded by deliveredmRNA is detectable 1, 2, 3, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66,and/or 72 hours in serum or target tissues after a single administrationof provided liposomes or compositions. In some embodiments, theexpression of the protein encoded by the mRNA is detectable 1 day, 2days, 3 days, 4 days, 5 days, 6 days, and/or 7 days in serum or targettissues after a single administration of provided liposomes orcompositions. In some embodiments, the expression of the protein encodedby the mRNA is detectable 1 week, 2 weeks, 3 weeks, and/or 4 weeks inserum or target tissues after a single administration of providedliposomes or compositions. In some embodiments, the expression of theprotein encoded by the mRNA is detectable after a month or longer aftera single administration of provided liposomes or compositions.

EXAMPLES

While certain compounds, compositions and methods of the presentinvention have been described with specificity in accordance withcertain embodiments, the following examples serve only to illustrate thecompounds of the invention and are not intended to limit the same.

Example 1. Synthesis of Compounds of Formula I

A. Compounds of formula I, such as T23 (the compound of formula III),can be made according to the route shown in Scheme 1:

As shown in Scheme 1, exemplary compounds of formula I are prepared fromL-lysine 1. L-lysine is first converted, via sodium nitrite and sulfuricacid, to a 6-amino-2-hydroxyhexanoic acid intermediate, which is treatedwith two equivalents of 2-decyloxirane to provide6-(bis(2-hydroxydodecyl)amino)-2-hydroxyhexanoic acid 3, thealpha-hydroxy acid functionality of which is protected with2,2-dimethoxypropane to yield 2,2-dimethyl-1,3-dioxolan-4-one 4.Protection of the secondary alcohols and deprotection of thealpha-hydroxy acid functionality of 5 yields 2-hydroxyhexanoic acid 6.2-Hydroxyhexanoic acid 6 is split into two equivalent portions, one ofwhich is converted to benzyl-protected alcohol 7 and the other isconverted to Cbz-protected acid 8. Alcohol 7 and acid 8 are esterifiedusing standard coupling protocols to yield ester 9. Subsequenthydrogenation to removal protecting groups affords the free acid 10,which was coupled intramolecularly to provide the lactone precursor 11.The final step required boron-mediated removal of TBS protecting groupsyields the final target compound T23 (Compound of Formula III).

B. Similarly, T23 (the compound of formula III) can be made according tothe route shown in Scheme 2:

As shown in Scheme 2, a short route to achieving T23 was achieved byexploiting direct intermolecular cyclization of the free a-hydroxy acid6a to form the lactone precursor 11. Upon completion, identicalboron-mediated removal of the TBS groups afforded the compound ofFormula III, T23.

C. T23 can be also made according to the route shown in Scheme 3:

Synthesis of Compound 2.1

To a mixture of Boc-Lys-OH (18 g, 73 mmol) and DIPEA (16 mL) in methanol(216 mL) at room temperature was added (2S)-1,2-epoxydodecane (40 g, 219mmol). The reaction mixture was heated at reflux overnight. The lightyellow clear solution was concentrated to give a yellow oil, which wasmixed with THF (120 mL), water (100 mL) and lithium hydroxide (6 g, 250mmol) and stirred at room temperature overnight. The reaction mixturewas then extracted with dichloromethane/methanol (9:1, 500 mL x 4). Thecombined organic layers were dried over Na₂SO₄. Filtration andconcentration gave 82 g crude product which was purified by flashchromatography on silica gel (1 kg, 0-35% methanol in ethyl acetate) toyield 38.6 g (81%) of 2.1 as an off-white solid.

Synthesis of Compound 3.1

A solution of compound 2.1 (38.6 g, 62.9 mmol) in anhydrousdichloromethane (200 mL) and trifluoroacetic acid (200 mL) was stirredat room temperature for 1 h. The reaction mixture was concentrated underreduced pressure. The residue was dried under vacuum to give 39.5 g(100%) crude product 3.1 that was used directly for the next stepwithout further purification.

Synthesis of Compound 4.1

To a mixture of compound 3.1 (39.5 g, 62.9 mmol) in 10% sulfuric acid(520 mL) at 0-5° C. (ice-water bath) with vigorously stirring, asolution of sodium nitrite (32 g, 464 mmol) in water (130 mL) was addeddropwise in over 2 h while keeping the internal temperature below 5° C.After the addition was finished, the reaction mixture was allowed towarm up slowly to room temperature and stirred overnight. The reactionmixture was then extracted with dichloromethane/methanol (9:1, 800mL×6). The combined organic layers were washed with saturated aqueousNa₂S₂O₃ solution and brine, then dried over Na₂SO₄. Filtration andconcentration of the filtrate gave 38 g crude product which was purifiedusing a Teledyne ISCO Combiflash automatic chromatography system (330 gRedisep silica gel column, 0-50% MeOH in CH₂Cl₂ gradient) to give 8.4 gof product 4.1 as light yellow foam (Yield: 73%, based on startingmaterial consumed). 21 g of starting material 3.1 (free base) was alsorecovered.

Synthesis of Compound 5.1

Pyridinium p-toluenesulfonate (4.15 g, 16.5 mmol) was added to asolution of compound 4.1 (6.05 g, 11 mmol) in THF/2,2-dimethoxypropane(40 mL/40 mL). The resulting mixture was stirred at 55° C. for 5 h and50° C. overnight. The solvents were removed under reduced pressure. Theresidue was dried under vacuum and used without purification.

Synthesis of Compound 6.1

The crude compound 5.1 was dissolved in DMF (30 mL). To this solutionwas added DMAP (269 mg, 2.2 mmol), imidazole (4.49 g, 66 mmol), andTBDMSCl (6.63 g, 44 mmol). The resulting solution was stirred at roomtemperature overnight. The solvents were removed under reduced pressure.The residue was partitioned between Et₂O (150 mL) and water (50 mL). Theorganic layer was separated, washed with brine (2×25 mL), dried overNa₂SO₄, and filtered. The filtrate was evaporated in vacuo and theresidue was purified by column chromatography on silica gel (0-20%EtOAc/hexane) to give 5.4 g (63%, over two steps) of the desired productas a colorless oil.

Synthesis of Compound 7.1 (HCl Salt)

To a solution of compound 6.1 (5.32 g, 6.8 mmol) in THF (65 mL) wasadded dropwise 0.5 N NaOH (16.3 mL, 8.2 mmol). The resulting mixture wasstirred at room temperature overnight. EtOAc (150 mL) was added. Themixture was acidified with 0.5 M HCl (40 mL). Then brine (60 mL) wasadded. The organic layer was separated, washed with brine (2×50 mL),dried over Na₂SO₄, and filtered. The filtrate was evaporated in vacuo.The residue was dried under vacuum to give 5.26 g (98%) of the desiredproduct as an off-white wax.

Synthesis of Compound 7.1 (Sodium Salt)

To a solution of compound 6.1 (6.5 g, 8.3 mmol) in THF (80 mL) was addeddropwise 0.5 N NaOH (20 mL, 10 mmol). The resulting mixture was stirredat room temperature overnight. Et₂O (200 mL) was added. The organiclayer was washed with brine (3×50 mL), dried over Na₂SO₄, and filtered.The filtrate was evaporated in vacuo to give 6.5 g (99%) of the desiredproduct as a colorless oil.

Synthesis of Compound 8.1

Benzyl bromide (1.08 mL, 9.1 mmol) was added dropwise to a solution ofsodium salt of compound 7.1 (6.5 g, 8.3 mmol) in DMF/THF (30 mL/30 mL).The resulting solution was stirred at room temperature for 18 h. Thesolvents were removed under reduced pressure. The residue was taken upin EtOAc (150 mL). The organic layer was washed with water (25 mL),brine (2×25 mL), dried over Na₂SO₄, and filtered. The filtrate wasevaporated in vacuo and the residue was purified by columnchromatography on silica gel (0-20% EtOAc/hexane) to give 6.31 g (91%)of the desired product as a colorless oil.

Synthesis of Compound 9.1

To a cold (0° C.) solution of compound 7.1 HCl salt (5.26 g, 6.74 mmol)in THF/pyridine (15 mL/10 mL) was added dropwise benzyl chloroformate(1.15 mL, 8.1 mmol). The resulting mixture was allowed to warm to roomtemperature and stirred overnight. An aliquot of the reaction mixturewas taken out for MS analysis. The result indicated the reaction did notgo to completion. Benzyl chloroformate (1.15 mL, 8.1 mmol) was added.The reaction mixture was stirred at room temperature for another 1.5 h,then diluted with EtOAc (200 mL). The organic layer was washed withwater (50 mL), 1.5 M HCl (2×50 mL), brine (3×40 mL), dried over Na₂SO₄,and filtered. The filtrate was evaporated in vacuo and the residue waspurified by column chromatography on silica gel (0-70% EtOAc/hexane) togive 2.78 g (45%) of the desired product as light yellow oil.

Synthesis of Compound 10.1

To a cold (0° C.) solution of compound 8.1 (3.5 g, 4.2 mmol) andcompound 9.1 (2.78 g, 3 mmol) in DCM (30 mL) was added DMAP (673 mg, 6mmol) and DCC (2.48 g, 12 mmol). The resulting mixture was allowed towarm to room temperature and stirred overnight. DCM was removed underreduced pressure and the residue was taken up in Et₂O and filtered. Thefiltrate was evaporated in vacuo. The residue was purified by columnchromatography on silica gel (0-20% EtOAc/hexane) to give 4.87 g (95%,contaminated with dicyclohexyl urea) of the desired product as acolorless oil.

Synthesis of Compound 11.1

To a solution of 10.1 (4.0 g, 2.36 mmol) in THF (anhydrous, 15 mL) in a100 ml Teflon flask at 0° C. was added dropwise a 70% wt/30% wtHF-pyridine solution (15 mL, 578 mmol). The resulting mixture wasstirred at room temperature for 2.5 h. Mass spectrometry analysisindicated completion of the reaction. The reaction solution was dilutedwith DCM (50 mL). The DCM solution was added to a mixture of DCM (200mL) and aqueous Na₂CO₃ solution (40 g in 180 mL of water) with rapidstirring. The DCM layer was separated. The aqueous layer was extractedwith DCM (150 mL). The combined organic phase was dried over Na₂SO₄ andevaporated. The light yellow oily residue was purified by silica gelcolumn (120 g) on an ISCO automatic chromatography system eluting with0-100% EtOAc in hexanes to give 2.66 g of 11.1 (77%) as a light yellowoil.

Synthesis of Compound 12.1

To a solution of 11.1 (2.66 g, 2.15 mmol) in THF (anhydrous, 70 mL) wasadded Et₃N (2.39 mL, 17.2 mmol), followed by TMSCl (1.49 mL, 11.8 mmol).The resulting mixture was stirred at room temperature overnight.Volatiles were removed. The residue was stirred with Et₂O (anhydrous,100 mL) for 20 min and filtered. The solid was rinsed with Et₂O(anhydrous, 2×20 mL). The combined filtrate was evaporated and residuewas dried under vacuum overnight to give 3.15 g of 12.1 (96%) as lightyellow oil.

Synthesis of Compound 13.1

To a suspension of dry Pd/C (5%, 1.6 g) in EtOAc (15 mL) was added asolution of 12.1 (3.15 g, 2.1 mmol) in EtOAc (70 mL). The resultingmixture was stirred under a hydrogen balloon overnight. It was thenfiltered through Celite. The Celite was rinsed with EtOAc (25 mL×3). Thecombined filtrate was evaporated to give 2.09 g of 13.1 (78%) as a lightyellow oil.

Synthesis of Target 23

To a solution of 13.1 (2.09 g, 1.6 mmol) in a mixture of DCM (anhydrous,60 mL) and CH₃CN (anhydrous, 30 mL) was added DIPEA (0.415 mL, 2.4mmol), followed by HATU (0.912 g, 2.4 mmol). The resulting mixture wasstirred at room temperature under N₂ for 16 h. Volatiles were removed.The residue was extracted with hexane (100 mL+25 mL×2). The hexaneextracts were combined and washed with aqueous NaHCO₃ (2×60 mL) and aq.HCl (5 mL 1 M HCl in 60 mL of H₂O). It was dried over Na₂SO₄ andfiltered. The filtrate was evaporated to give compound 14.1 as lightyellow foam which was dissolved in DCM (anhydrous, 25 mL). HCl indiethyl ether (2M, 6 mL) was added dropwise and the resulting mixturewas stirred at room temperature under N₂ for 3 h. Mass spectrometryanalysis indicated completion of the reaction. Solvents were removed bypurging with a nitrogen gas flow. The residue was washed with anhydrousdiethyl ether (10 mL×3) and dried under high vacuum to give 1.61 g ofTarget 23 as off-white solid (94%, two steps).

D. The compound of Formula IV, Target 24 (T24), can be made according tothe route shown in Scheme 4:

Synthesis of Compound 3.2

A solution of propargylamine (4.83 g, 87.7 mmol) and 1,2-epoxydodecane(40.8 g, 210.4 mmol) in EtOH (300 mL) was heated under reflux for 16 h.The solvent was removed under reduced pressure and the residue waspurified by column chromatography on silica gel (0-30% EtOAc/hexane) togive 32.8 g (88%) of the desired product as a light yellow solid.

Synthesis of Compound 4.2

To a cold (0° C.) solution of 3.2 (10.16 g, 24 mmol) in DMF (48 mL) wasadded sequentially DMAP (587 mg, 4.8 mmol), imidazole (5.72 g, 84 mmol),and tert-butyldimethylsilyl chloride (9.04 g, 60 mmol). The resultingmixture was stirred at 0° C. for 20 min. The ice bath was then removed,and the reaction was allowed to warm to room temperature and stirredovernight. DMF was removed under reduced pressure. To the residue wasadded EtOAc (200 mL), water (50 mL), and brine (30 mL). The organiclayer was separated, washed with brine (50 mL), dried over Na₂SO₄, andfiltered. The filtrate was evaporated in vacuo and the residue waspurified by column chromatography on silica gel (hexane) to give 14.55 g(93%) of the desired product as colorless oil.

Synthesis of Compound 6.2

To a cold (0° C.) solution of 4.2 (3.52 g, 5.4 mmol) in toluene (40 mL)was added dropwise 2.5 M n-BuLi (2.16 mL, 5.4 mmol). The resultingsolution was stirred at 0° C. for 30 min, then 1 M Et₂AlCl (5.4 mL, 5.4mmol) was added dropwise. After addition, the cloudy solution wasstirred at 0° C. for another 2 h, then a solution of 5.2 (375 mg, 2.88mmol) in toluene (2 mL) was added dropwise. After stirring for 30 min,the ice bath was removed, and the reaction was allowed to warm up toroom temperature and stirred overnight. The reaction was cooled with anice bath then Na₂SO₄.10H₂O (8.3 g) was added in one portion. Theresulting mixture was stirred vigorously for 2 h. The mixture wasfiltered and the filtrate was evaporated in vacuo. The residue waspurified by column chromatography on silica gel (0-5% EtOAc/hexane)twice to give 1.12 g (53%) of the desired product as a yellow oil.

Synthesis of Compound 7.2

To a solution of 6.2 (2.0 g, 2.56 mmol) in EtOH (50 mL) was addedpyridine (1.45 mL, 17.9 mmol) and 5 wt. % Pd/C (272 mg, 0.128 mmol). Theresulting mixture was degassed with Ar three times and then stirredunder 1 atm H₂ overnight. The mixture was filtered through a Celite plugwhich was washed with EtOH thoroughly. The combined filtrate and washeswere evaporated in vacuo to give 2.0 g of light yellow oil as a mixtureof the desired product and other inseparable byproducts. The crude wasused in next step without further purification.

Synthesis of Compound 8.2

To a solution of crude 7.2 (2.0 g) in THF (31 mL) was added 0.5 N NaOH(6.14 mL, 3.07 mmol) and MeOH (1.5 mL). The resulting mixture wasstirred vigorously at room temperature overnight. The solvent wasremoved under reduced pressure. The residue was taken up in Et₂O (120mL), and was washed with brine (3×30 mL), dried over Na₂SO₄, andfiltered. The residue was purified by column chromatography on silicagel (0-50% EtOAc/hexane) to give 739 mg (37% over two steps) of thedesired product as a light yellow oil.

Synthesis of Compound 9.2

To a solution of compound 8.2 (739 mg, 0.97 mmol) in DMF/THF (5 mL/10mL) at room temperature was added K₂CO₃ (201 mg, 1.46 mmol). Theresulting mixture was stirred for 20 min then benzyl bromide (127 μL,1.07 mmol) was added. The resulting mixture was stirred at roomtemperature overnight. The solvents were removed under reduced pressure.The residue was taken up in EtOAc (70 mL) and washed with water (10 mL),brine (15 mL), dried over Na₂SO₄, and filtered. The filtrate wasevaporated in vacuo and the residue was purified by columnchromatography on silica gel (0-10% EtOAc/hexane) to give 796 mg (97%)of the desired product as colorless oil.

Synthesis of Compound 10.2

To a cold (0° C.) solution of 8.2 (795 mg, 1.05 mmol) in THF (10.5 mL)was added sequentially 2,6-lutidine (128 μL, 1.1 mmol) and benzylchloroformate (157 μL, 1.1 mmol). After stirring for 15 min, the icebath was removed. The reaction was allowed to warm to room temperatureand stirred for 4 h. An aliquot of reaction mixture was taken out for MSanalysis. The result indicated the reaction did not go to completion.Then benzyl chloroformate (157 μL, 1.1 mmol) was added. After stirringat room temperature for another 1 h, the reaction was quenched withsaturated aqueous NaHCO₃ solution (25 mL). The mixture was stirredvigorously overnight. The mixture was diluted with EtOAc (70 mL). Theorganic layer was separated and the aqueous layer was extracted withEtOAc (20 mL). The combined organic layers were washed with 0.5 M HCl(20 mL), brine (2×15 mL), dried over Na₂SO₄, and filtered. The filtratewas evaporated in vacuo and the residue was purified by columnchromatography on silica gel (0-50% EtOAc/hexane) to give 663 mg (67%)of the desired product as a yellow oil.

Synthesis of Compound 11.2

To a cold (0° C.) solution of compound 9.2 (800 mg, 0.94 mmol) and 10.2(664 mg, 0.71 mmol) in CH₂Cl₂ (7.1 mL) was added DMAP (157 mg, 1.42mmol) and DCC (293 mg, 1.42 mmol). After stirring for 15 min, thereaction was allowed to warm up to room temperature and stirredovernight. CH₂Cl₂ was removed under reduced pressure. The residue wastaken up in Et₂O (50 mL). The white solid was removed by filtration. Thefiltrate was evaporated in vacuo. The residue was purified by columnchromatography on silica gel (0-10% EtOAc/hexane) twice to give 964 mg(79%) of product 11.2 as a colorless oil.

Synthesis of Compound 12.2

To a solution of 11.2 (5.04 g, 2.93 mmol) in THF (anhydrous, 15 mL) wasadded the 70% wt/30% wt HF-pyridine solution (20 mL, 770 mmol). Theresulting mixture was stirred at room temperature. Mass spectrometryanalysis after 2.5 h indicated complete reaction. THF was removed. Theresidual solution was diluted with DCM (50 mL). The DCM solution wasadded to a mixture of DCM (200 mL) and aqueous Na₂CO₃ solution (61 g in300 mL of water) with rapid stirring. The DCM layer was separated. Theaqueous layer was extracted with DCM (150 mL). The combined organicphase was dried over Na₂SO₄ and evaporated. The light yellow oilyresidue was purified by silica gel column (80 g) on an ISCO automaticchromatography system eluting with 0-100% EtOAc in hexane to give 2.85 gof 12.2 (77%) as a light yellow oil.

Synthesis of Compound 13.2

To a solution of 12.2 (2.85 g, 2.25 mmol) in THF (anhydrous, 70 mL) wasadded Et₃N (2.5 mL, 18 mmol), followed by TMSCl (1.5 mL, 11.9 mmol). Theresulting mixture was stirred at room temperature for 3 h. Volatileswere removed. The residue was stirred with Et₂O (anhydrous, 100 mL) for20 min and filtered. The solid was rinsed with Et₂O (anhydrous, 2×20mL). The combined filtrate was evaporated and residue was dried undervacuum overnight to give 3.29 g of 13.2 (94%) as a light yellow oil.

Synthesis of Compound 14.2

To a suspension of Pd/C (5%, 1.62 g, mmol) in EtOAc (10 mL) was added asolution of 13.2 (3.29 g, 2.11 mmol) in EtOAc (70 mL). The resultingmixture was stirred under a balloon of H₂ for 2 h. It was then filteredthrough Celite. The Celite was rinsed with EtOAc (3×20 mL). The combinedfiltrate was evaporated to give 2.78 g of 14.2 (99%) as a light yellowoil.

Synthesis of Compound 15.2

To a solution of 14.2 (2.78 g, 2.09 mmol) in a mixture of DCM(anhydrous, 40 mL) and CH₃CN (anhydrous, 20 mL) was added DIPEA (0.55mL, 3.14 mmol), followed by HATU (1.19 g, 3.14 mmol). The resultingmixture was stirred at room temperature under N₂ for 16 h. Volatileswere removed. The residue was extracted with hexane (150 mL). The hexaneextract was washed with aqueous NaHCO₃ (2×60 mL) and HCl. It was driedover Na₂SO₄ and filtered. The filtrate was evaporated to give 2.36 g(86%) of 15.2 as a light yellow gum.

Synthesis of Target 24

To a solution of 15.2 (1.09 g, 0.83 mmol) in DCM (anhydrous, 15 mL), HClin diethyl ether (2 M, 3 mL) was added dropwise and the resultingmixture was stirred at room temperature under N₂ for 3.5 h. Massspectrometry analysis indicated completion of the reaction. Solvent wasremoved by purging with a nitrogen gas flow. The residue was washed withanhydrous diethyl ether (20 mL×3) and dried under high vacuum to give875 mg of crude Target 24. 255 mg of crude Target 24 was washed withanhydrous acetonitrile (30 mL×3). The residue was dissolved in DCM(anhydrous, 2 mL) and added to a mixture of diethyl ether (anhydrous, 25mL) and HCl in diethyl ether (2 M, 0.5 mL) with stirring. Aftercontinued stirring for 30 minutes, the gummy solid was separated fromthe solution and was washed with anhydrous diethyl ether (5 mL×2). Itwas dried under high vacuum to give 200 mg (69%) of Target 24 as anoff-white foam.

Example 2. Exemplary Liposome Formulations for mRNA Delivery andExpression

This example provides exemplary liposome formulations incorporating thecationic lipids described in this application, for example, the compoundof formula III, for effective delivery and expression of mRNA encodingtherapeutic proteins in vivo.

Lipid Materials

In general, the formulations described herein are based on amulti-component lipid mixture of varying ratios employing one or morecationic lipids, one or more helper lipids (e.g., non-cationic lipidsand/or cholesterol-based lipids), and one or more PEGylated lipidsdesigned to encapsulate various nucleic acid-based materials. As anon-limiting example, the compound of Formula III(3,6-bis(4-(bis(2-hydroxydodecyl)amino)butyl)-1,4-dioxane-2,5-dione) isused in various formulations described herein. Exemplary helper lipidsinclude one or more of DSPC(1,2-distearoyl-sn-glycero-3-phosphocholine), DPPC(1,2-dipalmitoyl-sn-glycero-3-phosphocholine), DOPE(1,2-dioleyl-sn-glycero-3-phosphoethanolamine), DOPC(1,2-dioleyl-sn-glycero-3-phosphotidylcholine) DPPE(1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine), DMPE(1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine), DOPG(1,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol)), cholesterol, etc.Exemplary PEGylated lipids include a poly(ethylene) glycol chain of upto 5 kDa in length covalently attached to a lipid with alkyl chain(s) ofC₆-C₂₀ length, for example, PEG-2K. As non-limiting examples, liposomeformulations used in various examples described herein include thecompound of Formula III, DOPE, cholesterol and DMG-PEG2K at variousratios. For example, in some cases, the ratio of the compound of FormulaIII:DOPE:cholesterol:DMG-PEG2K is approximately 40:30:20:10 by weight.In other cases, the ratio of the compound of FormulaIII:DOPE:cholesterol:DMG-PEG2K is approximately 40:32:25:3 by weight.Unless otherwise specified, the below Examples include a mixture in theratio of the compound of Formula III:DOPE:cholesterol:DMG-PEG2K ofapproximately 40:30:25:5 by weight.

Messenger RNA Material

The formulations described herein may be used to deliver any mRNA, inparticular, therapeutic mRNA. As used herein, a therapeutic mRNA refersto an mRNA that encodes a therapeutic protein. The formulationsdescribed herein can also be used to deliver any modified or unmodifiedmRNA, or mRNA with naturally occurring sequences or codon-optimized.

As non-limiting examples, human Factor IX (FIX), codon-optimized FireflyLuciferase (FFL), codon-optimized human argininosuccinate synthetase(ASS1) messenger RNA, codon-optimized human Spinal Motor Neuron 1(SMN)mRNA were synthesized by in vitro transcription from a plasmid DNAtemplate encoding the gene, which was followed by the addition of a 5′cap structure (Cap 1) (Fechter, P.; Brownlee, G. G. “Recognition of mRNAcap structures by viral and cellular proteins” J. Gen. Virology 2005,86, 1239-1249) and a 3′ poly(A) tail of, e.g., approximately 250nucleotides in length as determined by gel electrophoresis. Typically,5′ and 3′ untranslated regions (UTR) are present in each mRNA productand are represented as X and Y, respectively. Example 5′ and 3′ UTRsequences are described below. The exemplary sequences of FIX, ASS1, andFFL mRNA used in the examples herein are listed below. Also shown arethe 5′ and 3′ UTR sequences.

Codon-Optimized Firefly Luciferase (FFL) mRNA: (SEQ ID NO.: 3)XAUGGAAGAUGCCAAAAACAUUAAGAAGGGCCCAGCGCCAUUCUACCCACUCGAAGACGGGACCGCCGGCGAGCAGCUGCACAAAGCCAUGAAGCGCUACGCCCUGGUGCCCGGCACCAUCGCCUUUACCGACGCACAUAUCGAGGUGGACAUUACCUACGCCGAGUACUUCGAGAUGAGCGUUCGGCUGGCAGAAGCUAUGAAGCGCUAUGGGCUGAAUACAAACCAUCGGAUCGUGGUGUGCAGCGAGAAUAGCUUGCAGUUCUUCAUGCCCGUGUUGGGUGCCCUGUUCAUCGGUGUGGCUGUGGCCCCAGCUAACGACAUCUACAACGAGCGCGAGCUGCUGAACAGCAUGGGCAUCAGCCAGCCCACCGUCGUAUUCGUGAGCAAGAAAGGGCUGCAAAAGAUCCUCAACGUGCAAAAGAAGCUACCGAUCAUACAAAAGAUCAUCAUCAUGGAUAGCAAGACCGACUACCAGGGCUUCCAAAGCAUGUACACCUUCGUGACUUCCCAUUUGCCACCCGGCUUCAACGAGUACGACUUCGUGCCCGAGAGCUUCGACCGGGACAAAACCAUCGCCCUGAUCAUGAACAGUAGUGGCAGUACCGGAUUGCCCAAGGGCGUAGCCCUACCGCACCGCACCGCUUGUGUCCGAUUCAGUCAUGCCCGCGACCCCAUCUUCGGCAACCAGAUCAUCCCCGACACCGCUAUCCUCAGCGUGGUGCCAUUUCACCACGGCUUCGGCAUGUUCACCACGCUGGGCUACUUGAUCUGCGGCUUUCGGGUCGUGCUCAUGUACCGCUUCGAGGAGGAGCUAUUCUUGCGCAGCUUGCAAGACUAUAAGAUUCAAUCUGCCCUGCUGGUGCCCACACUAUUUAGCUUCUUCGCUAAGAGCACUCUCAUCGACAAGUACGACCUAAGCAACUUGCACGAGAUCGCCAGCGGCGGGGCGCCGCUCAGCAAGGAGGUAGGUGAGGCCGUGGCCAAACGCUUCCACCUACCAGGCAUCCGCCAGGGCUACGGCCUGACAGAAACAACCAGCGCCAUUCUGAUCACCCCCGAAGGGGACGACAAGCCUGGCGCAGUAGGCAAGGUGGUGCCCUUCUUCGAGGCUAAGGUGGUGGACUUGGACACCGGUAAGACACUGGGUGUGAACCAGCGCGGCGAGCUGUGCGUCCGUGGCCCCAUGAUCAUGAGCGGCUACGUUAACAACCCCGAGGCUACAAACGCUCUCAUCGACAAGGACGGCUGGCUGCACAGCGGCGACAUCGCCUACUGGGACGAGGACGAGCACUUCUUCAUCGUGGACCGGCUGAAGAGCCUGAUCAAAUACAAGGGCUACCAGGUAGCCCCAGCCGAACUGGAGAGCAUCCUGCUGCAACACCCCAACAUCUUCGACGCCGGGGUCGCCGGCCUGCCCGACGACGAUGCCGGCGAGCUGCCCGCCGCAGUCGUCGUGCUGGAACACGGUAAAACCAUGACCGAGAAGGAGAUCGUGGACUAUGUGGCCAGCCAGGUUACAACCGCCAAGAAGCUGCGCGGUGGUGUUGUGUUCGUGGACGAGGUGCCUAAAGGACUGACCGGCAAGUUGGACGCCCGCAAGAUCCGCGAGAUUCUCAUUAAGGCCAAGAAGGGCGGCAAGAUCGCCGU GUAAY 5′ and 3′ UTRSequences X (5′ UTR Sequence) = (SEQ ID NO.: 5)GGACAGAUCGCCUGGAGACGCCAUCCACGCUGUUUUGACCUCCAUAGAAGACACCGGGACCGAUCCAGCCUCCGCGGCCGGGAACGGUGCAUUGGAACGCGGAUUCCCCGUGCCAAGAGUGACUCACCGUCCUUGACACG Y (3′ UTR Sequence) = (SEQ IDNO.: 6) CGGGUGGCAUCCCUGUGACCCCUCCCCAGUGCCUCUCCUGGCCCUGGAAGUUGCCACUCCAGUGCCCACCAGCCUUGUCCUAAUAAAAUUAAGUUGCAUC AAGCU or (SEQ ID NO.:7) GGGUGGCAUCCCUGUGACCCCUCCCCAGUGCCUCUCCUGGCCCUGGAAGUUGCCACUCCAGUGCCCACCAGCCUUGUCCUAAUAAAAUUAAGUUGCAUCA AGCUAliquots of 50 mg/mL ethanolic solutions of the compound of Formula III,DOPE, Chol and DMG-PEG2K are mixed in a molar ratio of 40:30:25:5 anddiluted with ethanol to 3 mL final volume. Separately, an aqueousbuffered solution (10 mM citrate/150 mM NaCl, pH 4.5) of FIX, ASS1, orFFL mRNA is prepared from a 1 mg/mL stock. The lipid solution isinjected rapidly into the aqueous mRNA solution and shaken to yield afinal suspension in 20% ethanol. The resulting nanoparticle suspensionis filtered, diafiltrated with 1×PBS (pH 7.4), concentrated and storedat 2-8° C. The final concentration of FIX mRNA is typically diluted toapproximately 0.20 mg/mL FIX mRNA (encapsulated), Z_(ave)=76 nm,PDI=0.08. The final concentration of ASS1 mRNA is typically diluted toapproximately 0.20 mg/mL ASS1 mRNA (encapsulated), Z_(ave)=78 nm(Dv(50)=46 nm; Dv(90)=96 nm). The final concentration of FFL mRNA istypically diluted to approximately 0.20 mg/mL FFL mRNA (encapsulated),Z_(ave)=75 nm, PDI—0.11. The final concentration of SMN mRNA istypically diluted to approximately 0.20 mg/mL SMN mRNA (encapsulated).Average particle size (Z_(ave))=71 nm, (particle size for 50% ofparticles was 44 nm or less (Dv(50))=44 nm; and the particle size for90% of the particles was 93n or less (Dv(90)=93 nm)).Exemplary Formulation Comprising T23:

Aliquots of 50 mg/mL ethanolic solutions of the compound of Target 23,DOPE, Chol and DMG-PEG2K were mixed in a molar ratio of 40:30:25:5 anddiluted with ethanol to 3 mL final volume. Separately, an aqueousbuffered solution (10 mM citrate/150 mM NaCl, pH 4.5) of EPO mRNA wasprepared from a 1 mg/mL stock. The lipid solution was injected rapidlyinto the aqueous mRNA solution and shaken to yield a final suspension in20% ethanol. The resulting nanoparticle suspension was diafiltrated with1×PBS (pH 7.4), concentrated and stored at 2-8° C. The finalconcentration of EPO mRNA is typically diluted to approximately 0.20mg/mL EPO mRNA (encapsulated). Z_(ave)=80 nm, PDI=0.11.

Exemplary Formulation Comprising T24:

Aliquots of 50 mg/mL ethanolic solutions of the compound of Target 24,DOPE, Chol and DMG-PEG2K were mixed in a molar ratio of 40:30:25:5 anddiluted with ethanol to 3 mL final volume. Separately, an aqueousbuffered solution (10 mM citrate/150 mM NaCl, pH 4.5) of EPO mRNA wasprepared from a 1 mg/mL stock. The lipid solution was injected rapidlyinto the aqueous mRNA solution and shaken to yield a final suspension in20% ethanol. The resulting nanoparticle suspension was diafiltrated with1×PBS (pH 7.4), concentrated and stored at 2-8° C. The finalconcentration of EPO mRNA is typically diluted to approximately 0.20mg/mL EPO mRNA (encapsulated). Z_(ave)=78 nm, PDI=0.14.

Example 3. In Vivo Results

CD-1 Mice (N=4 per group) were injected with a 0.20 mg/mL formulation ofeither Target 23-based LNPs or Target 24-based LNPs loaded with hEPOmRNA (1.0 mg/kg). Serum levels of hEPO were monitored at 6 hr and 24 hrpost-dose. See FIG. 1. Liver enzymes (ALT/AST) were measured 24 hrpost-administration. See Table 1.

TABLE 1 Liver enzymes levels in wild type mouse sera after treatment viahEPO mRNA loaded LNPs. Formulation ALT Levels AST Levels Target 23 LNP107 ± 37 92 ± 17 Target 24 LNP  77 ± 16 73 ± 11

EQUIVALENTS

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, many equivalents to the specificembodiments of the invention described herein. The scope of the presentinvention is not intended to be limited to the above Description, butrather is as set forth in the following claims:

We claim:
 1. A lipid nanoparticle comprising a compound of formula III:

or a pharmaceutically acceptable salt thereof.
 2. The lipid nanoparticleof claim 1, comprising a polynucleotide.
 3. The lipid nanoparticle ofclaim 2, wherein the lipid nanoparticle is a liposome.
 4. The lipidnanoparticle of claim 3, further comprising one or more non-cationiclipids, one or more cholesterol-based lipids and/or one or morePEG-modified lipids.
 5. The lipid nanoparticle of claim 4, wherein theone or more non-cationic lipids are selected from DSPC(1,2-distearoyl-sn-glycero-3-phosphocholine), DPPC(1,2-dipalmitoyl-sn-glycero-3-phosphocholine), DOPE(1,2-dioleyl-sn-glycero-3-phosphoethanolamine), DOPC(1,2-dioleyl-sn-glycero-3-phosphotidylcholine) DPPE(1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine), DMPE(1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine), DOPG(1,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol)).
 6. The lipidnanoparticle of claim 4, wherein the one or more PEG-modified lipidscomprise a poly(ethylene) glycol chain of up to 5 kDa in lengthcovalently attached to a lipid with alkyl chain(s) of C₆-C₂₀ length. 7.The lipid nanoparticle of claim 3, wherein the liposome has a size lessthan about 250 nm, 200 nm, 150 nm, 100 nm, 75 nm, or 50 nm.